Final Post

As the title says, this is my final blog post, for this module. This has probably been one of the most challenging university projects in being consistent at producing weekly blog posts for two different modules. However, it has been one of the most interesting and engaging projects I have completed to date. 

Some of the key take home messages are that Climate change is increasing the extremity of weather. However, this should not be seen as a future threat, this is happening now, and has been for a while. Extreme weather is not new and figure 1 clearly shows this. 

Climate change is not only changing the frequency of these events, but also seasonality, intensity and duration. Although there is not always the evidence to suggest that Climate Change is causing these changes in weather, and is often hard to differentiate from natural variabilities. I believe that all extreme weather events should be considered in the context of climate change

Figure 1: Major weather events pre 2010

Source: http://site.destinationgreen.com/extreme-weather-link-can-no-longer-be-ignored/

Vulnerability to these changes is what is important. We must focus on adaptation, mitigation and effective management strategies in to reduce the risk of these events, especially for those in extreme poverty.

Climate change down under

Lightening in Sydney 8/12/16

Source: https://www.instagram.com/p/BNwV5JSDqj2/

Most of Australia can expect a hotter than average December, with temperatures being forced up by both regional climate patterns and a global upward trend. Drier- than- average conditions in December, with a 70-80% change of below- average rainfall is expected across most of the eastern part of the country.

The higher than usual pressures were due to a climate force known as the Southern Annualar Mode, which is associated with reduced rainfall and higher temperatures (Lim, 2016). It was forcing wind systems further north than normal, holding monsoon weather at bay while moving air far across the continent.

Forest fires

Australian Summers and forest fires seem to go hand in hand. 

Warmer temperatures and reduced rainfall, has resulted in severe fire danger for parts of Australia. This winter has been the second- wettest on record, this encouraged grass growth, which prompts concerns about fast- running grass fires. 

Cyclone season

Cyclone season is not set to begin until January. Last season there was only 3 cyclones, due to an exceptionally long El Nino which is a record low. This season is expected to be above- average- 11 cyclones has been forecasted. However, there are worries:

"We don't want people to be complacent because not much happened last year... it wasnt typical by any means."

Thunderstorms

Severe thunderstorms are projected to be more common in east Australia, up to 30% in some parts. However, unlike heat and rainfall projections, links between climate change and thunderstorms in Australia are far lessunderstood.

Thunderstorms can be dangerous due to accompanying winds, lightning and flash flood, as well as their potential to rupture pollen into tiny particles that can be inhaled into the lungs. Eight people in Australia last week sadly lost their lives due to "thunderstorm asthma".

Is this climate change?

Australia has warmed 0.9℃ since 1910 and can be expected to warm a further 0.6 ℃ to 5.1℃ by 2090, depending on GHG reductions.

"Australian climate patterns were being influenced by the long- term increasing trend in global air and ocean temperatures" (Nom, 2016). Although it is difficult to differentiate between the impact of climate change, compared with local patterns and drivers, climate change is definitely playing a role in their weather and climate.

Concluding thoughts

All weather events should be considered in the context of climate change. Heatwaves and reduced rainfall pose the greatest threat to Australian health and livelihoods. Thunderstorm Asthma is not the only health risk associated with climate change.  Here is an article on other associated health risks in Australia.

Predicting health risks is a lot harder than extreme weather, therefore effective management needs to be put in place. Early warning systems, vulnerability mapping, and public health education, are just some of the ways to do this.

COP22

World Climate Simulation

This blog is inspired by the World climate simulation, that we did last week as part of this module. For those that are not part of this module, or were not there, we had to act as a negotiator at the United Nations Climate Change negotiations. In the 3 hours, teams from each region had to negotiate to try and get temperatures down to 1.5℃. I think we managed to get it down to 2.1℃ . It proved how challenging it can be to reach an agreement with between different regions, that have different motivations. It also showed how complicated the politics is, and how tensions can rise very quickly.

The exercise is framed by current climate change science, using the interactive C-ROADS computer simulation which allows participants to find out how their proposed policies impact the global climate system in real- time. We went into this having very limited knowledge on COP (Conference of the parties of the united Nations agreement on climate change), and how it worked. however, by the end of the sessions, we left with more knowledge and understanding.

Below is a video of how the simulation works. I would definitely encourage students (not only geography), schools, lecturers, businesses, leaders, everyone to get involved.

Mock Video climate simulation

So what does this have to do with Extreme weather and climate change?

COP22 was held in Marrakesh 7-18th November 2016.

During COP22 a new report 'unbreakable: Building the resilience of the poor in the face of natural disasters' was released by the World bank and the Global Facility for Disaster Reduction and recovery (GFDRR). It warns that natural disasters are a greater impediment to ending global poverty than previously understood, and underscores the urgency for climate- smart policies that better protect the world's most vulnerable.

The study of 117 countries, revealed how natural disasters which are being exacerbated by the effects of climate change, and are disproportionately impacting the worlds poorest regions. Extreme weather forces nearly 26 million individuals into poverty each year, which is 60% higher than all other estimates.

Stephanie Hallegate, an economist who led preparation of the report said in a statement:

"Countries are enduring a growing number of expected shocks as a result of climate change. Poor people need social and financial protection from disasters that cannot be avoided. With risk policies in place that we know to be effective, we have the opportunity to prevent millions of people from falling into poverty."

The latest Global Climate Risk index was also unveiled at COP22. It finds four of the world's top ten countries worst hit by extreme climate events last year were in Africa.

Table 1: The climate risk index for 2015: the 10 most affected countries

Source:http://germanwatch.org/de/download/16411.pdf

Heavy rainfalls due to the intensified monsoon in Southern Eastern Africa which started in December 2014 and continued throughout January and beyond, had disastrous consequences for infrastructure, agriculture and food security. As shown in the table Mozambique (1st), Malawi (3rd) and Madagascar (8th) were the hardest hit countries by the floods resulting from the torrential rainfalls.

Africa is home to some of the most poorest regions, and is also one of the most affected by extreme weather and climate change. Climate change is increasing the variation of rainfall in many regions, seeing long droughts, followed by extreme precipitation events. To find out more about this see my blog on Water and Environmental change in Africa, which looks at the changing distribution of rainfall, and the impacts this has on access to water.

Action therefore needs to be taken to protect the lives that are most affected by climate change:

"Adaptation finance is not just an abstract numbers game. It's about providing women famers in Africa with seeds to plant drought- resistant crops and foe their families; its about building seawalls so millions who lived in coastal areas survive rising sea levels."

Adaptation is key to the survival and development of Africa, other developing nations and the rest of the world. $100bn per year was promised by developed counties to help the most vulnerable countries adapt and mitigate the effects of climate change. However, at COP22, developed and developing countries disagreed over the distribution of funding between mitigation and adaptation efforts. A roadmap drawn up by developed countries and presented at Marrakesh allocated just 20% of climate finance to efforts to limit the damage caused by climate change. The remaining 80% of this money would be spent on mitigation. In other words, cutting greenhouse gas emissions.

However, I believe that this is an unfair distribution, as the need for adaptation is not necessarily more important than mitigation, but it is particularly important in developing countries, which are the hardest hit by climate hazards such as droughts and floods.

Forest Fire in Israel

The forest fire in Israel has been in the news this weekend. After yesterday's post, on how Climate Change is enabling more extreme forest fires, I think it is important to show that this is a problem happening now, and is affecting many.

In the past week in the Jerusalem Hills area alone, fires have destroyed > 1,250 acres of forest, and as of last night, the firefighters were still battling blazes. The number of forest fires in Israel have not risen in recent years, in fact over the past two years they have been declining. However, the magnitude of these fires in the past few years is unprecedented. This change has been linked to climate change:

"Winter is beginning later, and the months of November and December have become very dry, with strong winds. Continuous dry, strong winds, not only dry the laundry, but also the vegetations, and turns it into highly flammable material".

Israel is not the only place to be affected by Forest fires in the past week:

• Peru's forest's are being affected by fires
• Today there are 24 large wildfires currently burning throughout the Southern United States totalling > 130,000 acres

Climate Change Setting the Forests Alight?

Wildfires 

Wildfire are typically started accidentally by humans, or by natural causes such as lightening. These 'ignition' events start the fire, however, do not have a major impact on the scale of the fire. It is climate conditions that largely determines the scale ie. precipitation and temperature. The amount of vegetation is also an important factor (Abatzoglou, 2016).

As areas, have become warmer and drier due to climate change, there has seen an increase wildfires.

Is this climate change?

How does warming temperatures increase wildfire risk?

• Longer fire seasons due to earlier spring snow melt. Summer heat builds up more quickly, and warm conditions extend further into fall.
• Drier conditions will increase the probability of a fire occurring. Higher temperatures, will increase rates of evaporation, and increase wildfire risk areas, where there is lower rates of precipitation.
• Increased frequency of lightning is expected as thunderstorms become more severe.
• More fuel for forest fires through increased insect infestation such as the Mountain pine beetle, from higher temperatures, which results in more dead and high combustible trees.

Future global projections

Figure 1: Predicted fractional change in fire probability for the period 2010-20139 and 2070-2099 for the average of sixteen climate models used for the 2007 IPCC report

Source:http://onlinelibrary.wiley.com/doi/10.1890/ES11-00345.1/full

Large increases in fires are expected over the globe by the end of this century. For the 2010-2039 period, models predict that 8% of the world will see a decrease in forest fires, whereas 38% will see increases. The models are however, too uncertain to predict fire probability for the other 54%. The decreases are mainly concentrated in the tropics and sub-tropics, and the increase in fires will be predominantly in the biomes with already warm climates. For the 2070-2099 period the magnitude and agreement in the direction of change increases substantially. The models agree that 20% of earth will see decreases, and 62% increases, and models are uncertain for 18% of land areas. The decreases will mainly be in the tropics, and the mid- to high-latitudes are to see increases (Moritz, 2012).

The authors found that future fires in many areas will be primarily driven by air moisture availability. Forests in the boreal region are one of the most vulnerable to projected increases in fires. Russian and Canadian boreal forests are at increasing risk due to rapid temperature increases (stocks, 1998), as well as much of Scandinavia (Kelly, 2013).  In the U.S, the regions which are at most risk from increased fires are the tundra regions of Northern Alaska, and the West, with Arizona and Colorado (Moitz, 2012).

Western United States

Earlier this year, a study was published in the Journal Proceedings of the National Academy of Sciences, called 'Impact of Anthropogenic climate change on wildfire across Western US forest'.  This study says that human- induced climate change has doubled the amount of area that is affected by forest fires in Western US, in the last 30 years. Due to increased temperatures, which is turning many areas semi- arid and arid, wildfires are spreading across an additional 16,000 sq miles, than they would have otherwise. 

The main cause of increase forest fires is attributed to warmer temperatures drying the land, by removing moisture out of plants, trees, dead vegetation, the ground and soil, as warmer air can hold more moisture. Temperature increases, resulting in a drying effect is evident in the rise of more fires. However, the study does state that climate change is not the only factor causing increasing forest fires. Direct human actions, and long- term natural climate oscillations over the pacific ocean, play a role (Abatzoglou, 2016).

With this being said temperatures are increasing at around twice the rate in Western US compared to the global warming average. Therefore, climate change should definitely not be dismissed in how big of a factor it is. With wildfire seasons, number of wildfires, and total area affected by wildfires, there has been rapid increases in the past 30/ 40 years, and the future will only see more of these events.

Economic impacts

Since 2010, 10 forest fires in the US have caused at least US$1 billion in damages each, which is mainly from the loss of homes, infrastructure, and firefighting costs. In 2015 across the whole country, wildfires burned > 10 million acres, this is the highest annual total acreage burned since 1960, when recording began. The costliest fire occurred in California, where > 2,500 structures were destroyed in just 2 wildfires. Here insured loses alone exceeded $1 billion.

Other impacts

Beyond the direct economic impacts, there are many other implications of wildfires. Several public health risks are related to wildfires. Smoke reduces air quality and can cause eye and respiratory illness. The young children and the elderly, are at particular risk. A 2012 study estimated that ~340,000 people die each year from long- term health effects, associated with smoke from forest fires.

Wildfires can have ecological implications, causing ecosystem changes. They also release large amounts of co2, which further add to the GHG's already in the atmosphere, and contribute to more climate change. Furthermore, soot that settles on snow and ice cause them to absorb more heat, and therefore melt faster.

Concluding thoughts

Warmer temperatures are causing forest fires to increase, not only in quantity, but also the amount of land that is being affected. We are also seeing prolonged wildfire seasons. However, it is important to realise, as in all cases that climate change is not the only blame. Forest fires can be naturally occurring, and also can be caused by humans, however, the effects of climate change is making this event much more extreme across the globe. Therefore, mitigation and adaptation efforts need to be adopted and put in place immediately, to reduce the risk of wild fires.

The current change in climate in transforming our landscape, and fire is one of the tools it uses. As temperatures rise, we should expect to see more of it, in more places.

The SuperMoon and Global Warming: A glimpse into the future?

The Rare Supermoon that dominated the skyline, has been a hot topic in this week's news.

The rare supermoon which dominated the skyline for many, presented a natural wonder for many stargazers, however, there are devastating side effects related to this lunar event which has seen high tides and flooding in parts of America.

Last Mondays supermoon meant that the moon has been the closest to the Earth, than it has been in nearly 70 years. A supermoon happens when the full moon coincides with the lunar orb's closest approach to Earth during its orbit. The full lunar dusk appeared 14% bigger and 30% brighter than usual. One of the effects of the supermoon is stronger high tides due to the increase gravitational pull.

Miami, as well as many other areas, saw heavy coastal flooding. The supermoon increased the effect of the seasonal king tides- the highest predicted high tide of the year at a coastal location, which occurs once or twice a year- caused low lying areas to be immersed in water.

According to the New York Times:

"These so-called king tides, are the most blatant example of the interplay between rising  seas and the alignment of the moon, sun and Earth. Even without a drop of rain, some places flood routinely".

Rising Sea Levels

Coastal areas prone to flooding see higher tides monthly due to spring and proxigean tides. When they occur together the impacts are worse, but not catastrophic. If you were to add a third force for example a storm, things can deteriorate very quickly, creating storm surges and inundating low low lying areas.

Now add sea level rise into the picture. One of the main causes of coastal flooding is the rise of sea levels. Sea Level rise is caused primarily by two factors related to global warming (1) melting land ice at the poles; and (2) thermal expansion of seawater as the oceans warm. Tide gauge measurements has shown that sea level has risen by an average of 1.7 ± 0.3mm/ year since the 1950s. However, sea level rise has accelerated especially since the 1990s (Nicholls, 2010) causing the sea levels to rise by 3.4± 0.4mm per year. Since 1993 it has risen 85mm (figure 1).

Figure 1: Global sea level rise 1993-2016

Source: http://climate.nasa.gov/vital-signs/sea-level/

Modelling studies (figure 2) have shown that by 2100 sea level rise will range from 0.57 to 1.10m, with the maximum rate of sea level rise reaching 17mm/year according to the RCP8.5 pathway (Jevrejeva, 2012). 

Figure 2: Sea level projections 2100 with RCP scenarios

Source: http://www.sciencedirect.com/science/article/pii/S0921818111001469

Risk

'At the UN COP21 climate change summit in Paris December 2015, a target was set to limit global temperature rise to below 2℃'. May 2016, Christian aid released a report 'Act now pay later: protecting a billion people in climate- threatened coastal cities'. They detailed how by 2060 more than 1 billion people will be at risk from rising seas, flooding, extreme weather and storm surges caused by climate change.

The US who is one of the biggest emitters of GHGS, is likely to suffer most from coastal climate change, due to the value of exposed property, business, investment and other assets. 

Miami 

The coastal city this week hit headlines due to flooding. With 4.7 million residents, it is the top 9th city at risk in terms of population, but tops the list in financial terms, with > US$3.5 trillion worth of assets predicted to be exposed to extreme weather and flooding by 2070. Below shows a map (figure 3) of the areas that would be underwater in Miami if sea levels rose by 6 foot, that is 32,986 homes. 

Figure 3: Underwater homes in Miami

Source: http://cdn1.blog-media.zillowstatic.com/3/Miami-f0ec46.png

The flood this week, is just one of many issues the Miami area has faced because of rising sea levels. A university of Miami study published earlier this year found that flooding from rising tides has increased 400% since 2006. They also found that rising sea levels increased the frequency of rain- induced flooding events by 33%, because the higher sea levels reduced the effectiveness of gravity- based drainage systems. 

Thus in 2014, the city of Miami beach invested at least US$400 million in replacing old gravity based drainage systems with a new pumped-based systems throughout the most flood- prone areas. They are also investing into raising street heights. 

Concluding thoughts

The flood this week was not necessarily directly caused by climate change,  however sea level rise due to warmer temperatures has increased the magnitude of it.

Flooding in Miami is highly predictable, this low-lying area is already prone to flooding, especially due to monthly high tides, its porous limestone geology, and ineffective drainage systems. Therefore, it is not to say that sea level rise is causing flooding, because that is not the case. But climate change has meant that this area has become more susceptible to flooding- 'When it rains it floods', and there is simply more flooding. And this will get worse.

Climate change here is no longer seen as a future threat, and an expensive one it is. Is this a glimpse into the future for the rest of the world?

North East Brazils Drought

Droughts

While Climate Change has increased precipitation in some places- as seen in last week's post, other regions have seen drying trend contributing to drought (Trenberth, 2007). Droughts are not only caused by lack of rainfall, but also increased evaporation from soil and vegetation, associated with warming (Dai, 2011).

There has been a global trend, that has seen an increase in drier, hotter areas and dry regions becoming drier, which can both be traced to human influence. The increase in GHG emissions have contributed significantly to this recent drying, by driving warming over the sea and land (Dai, 2011).

There is considerable disagreement about the concept of drought. In North East Brazil, based on rainfall records meteorologists, dispute some Brazilian scientists and policy makers claims to how long the region has been experiencing drought for (Wilhite, 2009).

Climate change and Drought- NE Brazil

A recent study published this year- 'Drought in NorthEast Brazil- past, present and future' suggests that the droughts which have traditionally affected this region are being worsened by the effects of climate change.

Droughts have been recorded in this region since the Portuguese Colonisation in the early C16th. However, the droughts are getting worse and scientists warn that this could lead to desertification of the region. The latest drought, which began in 2012, is the worst reported for over a century.

Figure 1: Rainfall anomaly (mm month^-1) during the peak rainy season (february- May) in Northeast Brazil from 1951- 2014

source:http://link.springer.com/article/10.1007/s00704-016-1840-8

ENSO does influence interannual variability in this region. However, of the most recent, only the droughts occurring in 1998, 2002 and 2012 occurred during ENSO years (Figure 1).

This region covers 18% of Brazil's total area and is home to 53 million people. With 34 inhabitants per sq mile, it is the most densely populated semi- arid region in the world. The combination of lower- than- average rainfall and land-use changes due to rapid population growth and increase in economic activity, are exacerbating the impacts of drought.

What does the future hold?

Future climate projections show temperature increases, rainfall reductions, and an increase in the tendency for drought and aridification in this region.

This report's analysis of rainfall, temperature, and dry spell anomalies, confirmed the IPCC (2014) projections of increases in the severity and duration of droughts by late c21st, but low confidence for the first half of the century (Figure 2).

figure 2: Past and Projected temperature and precipitation change 

Source: https://www.ipcc.ch/report/ar5/syr/

The author says

 "Climate change will extract a heavy price from the northeast. Is it inevitable? Today there is only one certainty. In the future, there will be longer and hotter drought periods."

"Climate projections generated by the climate model suggest that from now on, more severe and prolonged droughts will be the rule, not the exception."

The projected future in NE Brazil of increasing frequency and length of dry spells, and droughts, has created much concern among natural resource managers, farmers, development specialists, researchers, and policymakers.  Water security, Food security, and Energy security, are at further risk due to these changes, which will in turn affect the sustainable development of this region.

This report references (Wilhite, 2014), that the current drought in NE Brazil has:

"Sparked a new round of discussions on improving drought policy and resilience to drought, as well as management at the federal and state levels in the region"

However, it is argued by Jan Rocha:

"The alarming but very possible scenario is almost completely ignored by politicians, who over the decades have used the droughts to further their own careers."

Concluding thoughts

Although drought and aridification on their own do not cause land degradation, they can make the land more vulnerable to human- induced degradation. Therefore, if not already, climate change will become the biggest challenge for North East Brazil, intensifying this environmental phenomenon. Therefore a number of obstacles will need to be identified and dealt with through appropriate policies, in order to reduce the risk for local people.

Trump: A NEW PLANETARY DISASTER?

"We're going to cancel the Paris climate agreement- unbelievable- and stop all payments of the United States dollars to UN global warming programs."

Donald Trump who believes that climate change is a Chinese conspiracy to make US manufacturing non-competitive is now the new PRESIDENT OF THE UNITED STATES!

What does this mean for the future?

Figure 1: Past and future projections of US carbon emissions based on US presidency

Source: http://www.luxresearchinc.com/news-and-events/press-releases/read/trump-presidency-could-mean-34-billion-tons-more-us-carbon

As the world looks to reduce carbon emissions following the 2015 Paris Agreement on Climate change, Lux Research finds that, Trumps presidency could see these emissions rising again (Figure 1). Trumps vision includes greater production of fossil fuels- in particular coal, cancelling Obama's clean power plan and withdrawal from the Paris agreement.

With the United States, already at number 2, of top emitters of GHGS (WRI, 2014) . Trumps presidency could see an increase in the utilisation of coal power stations, dependency on other GHGs, and a reduction in renewables. This will cause unprecedented increases in temperature, and, in turn, have further massive global implications on extreme weather.

More rain?

Precipitation changing with climate change

Figure 1: Observed change in annual precipitation over land 

Source:http://oceanservice.noaa.gov/education/pd/climate/factsheets/howprecipitation.pdf

Precipitation is the general term for rainfall, snowfall and other forms of frozen or liquid water falling from the clouds. The type of precipitation that occurs is greatly dependent on the temperature and weather at the time (IPCC, 2007).

Precipitation varies from year to year, constantly changing the amount, intensity, frequency and types. Precipitation has increased in many regions of the world and decreased in others (figure 1), with little or no net change in the total amount of precipitation (Trenberth , 2011).

Observed changes

'Precipitation has increased in the Eastern parts of North and South America, Northern Europe, and Northern and Central Asia. Precipitation decreases have been observed in the sub tropics and the tropics outside of the monsoon trough, namely the Sahel, the Mediterranean, Southern Africa and Southern Asia' (Trenberth, 2007).

Some areas have experienced widening swings between the two precipitation extremes. An example of this is the East African region. This region typically has a bi-modal annual rainfall cycle. The past 30 years has seen a gradual drying of the long rain season, and increased rainfall in the short rain season (figure 2). To read more on this Visit my Blog Post this week on Climate Change in East Africa. 

Figure 2: Percent of normal precipitation in East Africa, 2011

Source: NOAA Climate Prediction Center via Weather Underground

Can this not be natural variability?

Local and regional changes in precipitation largely depend on atmospheric circulation patterns determined by El Nino, the North Atlantic Oscillation and other patterns of variability.  Trenberth (2010) found that the global patterns of variations are dominated by large-scale patterns of change in precipitation associated with ENSO. A study based on the rainfall trends in the Philippines between 1951- 2010 found that the statistically significant drier conditions are related to El Nino, and the statistically significant wetter conditions are related to La Nina. The results suggested a trend of the dry season (January- March) becoming drier and the west season (July- September) becoming wetter.

Due to the natural variability in rainfall, it can be difficult to detect changes in rainfall patterns. Not only does El Nino make wet areas water, it also contracts storm tracks towards the equator, and that is the opposite effect of climate change. So, to separate the signal of climate change from natural variability, Marvel (2013) looked for both increased rainfall in wet areas and a shift in storm tracks away from the equator, which cannot happen naturally. This is exactly what they found.

Therefore, as also found in Scott (2010), natural variability arguably cannot explain the observed intensity and distributional changes in precipitation. Rather these are consistent with a combination of natural factors and human influence.

How is climate change affecting Rainfall?

There is more and more evidence that human- induced climate change, is changing the hydrological cycle, especially extreme weather events.

A study on the Increased record- breaking precipitation events under global warming has shown that in 'the last 3 decades the number of record breaking events has significantly increased in the global mean' (Figure 3). They found that there was 12% more of these events from 1981- 2010, compared to a scenario without global warming. In 2010 there was a 26% chance that the increase rainfall events were caused by climate change.

Southeast Asia had an increase of up to 56%, Europe 31% and Central United States 24%.

Figure 3:  Annual observed record-breaking anomaly between 1981 and 2010

Source: https://www.researchgate.net/publication/280223472_Increased_record-breaking_precipitation_events_under_global_warming

What is the relationship between rainfall and temperature?

The Clausius- Clapeyron equation is a good predictor for changes in extreme rainfall intensities- The higher the temperature of the air, the higher its potential to hold more moisture. This greater amount of moisture in the air translates into stronger downpours. The relationship predicts a 7% increase in water vapour per ℃ of warming. Not only does increased moisture mean heavier rainfall, but also less frequent and shorter rains, as it takes longer to recharge the atmosphere with moisture.

The future?

Climate models suggest that increasing GHG's in the atmosphere will change precipitation patterns in 2 main ways: 

1. There will be a shift in a strengthening of existing precipitation patterns- The wet areas will get wetter and the dry areas will get drier.
2. Changes in atmospheric circulation- Storm tracks will move away from the equator and towards the poles

IPCC Models

IPCC models indicate that with a warmer climate, precipitation will increase in the areas of regional tropical precipitation maxima. Specifically over the tropical pacific, with general decreases in the sub-tropics, and increases at high latitudes (IPCC, 2007).

Globally the average mean water vapour, evaporation and precipitation are projected to increase.

Figure 4:Changes in extremes based on multi-model simulations from nine global coupled climate models

source: https://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch10s10-3-6-1.html

As shown in Figure 4, intensity of precipitation events is projected to increase, particularly in tropical and high latitude areas. where there are general increases in mean precipitation. Even in areas where mean precipitation decreases, precipitation intensity is projected to increase, with variability. The mid- continental regions are at great risk of drought due to the tendency for drying during summer.

Concluding thoughts

Rainfall patterns are constantly changing; however increasing temperatures has meant that these precipitation events are becoming more and more extreme. Extreme precipitation events are typically defined as floods and droughts. Floods are associated with extremes in rainfall, while droughts are associated with a lack of precipitation and often very high temperatures (Trenberth, 2011). Todays post aimed to provide an insight into how rainfall patterns have changed and how they are projected to change in the future. 

Next week's blog will focus on how these changes have affected North East Brazil in terms of Drought.

Recent News

4th Earthquake in 3 months hits Central Italy- 30th October 2016

A 6.6 magnitude tremor has injured 20 people. Aftershocks were continuing in this region early this morning.

Figure 1: Earthquakes in Italy August- October 2016

The Israeli emergency body dedicated to dealing with natural disasters have therefore started monitoring a tsunami warning issued for the Mediterranean Sea.

At least 22 killed in Egypt Floods- 30 October 2016

Due to torrential rains causing flooding in parts of Egypt, at least 22 people were killed and 72 injured.

3 Children Killed as flooding hits Indonesia's Gorontalo Province- 31st October 2016

Flash floods due to heavy rains in Indonesia. 3 children were swept away by strong current of a river and bodies were later found. Four other children who were also swept away have survived.

3 Typhoons expected to hit the Philippines in November- 31st October 2016

A maximum of 3 typhoons may enter the Philippine area of responsibility (PAR) in November. The PAGASA agency is currently monitoring a low pressure area (LPA) that was spotted 1,240 km east of Mindanao, outside PAR, which may intensify into a typhoon within 48 to 72 hours.

video 1: Typhoons in phillipines 

Source: http://news.abs-cbn.com/video/news/10/31/16/pagasa-expect-up-to-3-typhoons-in-november

In the space of 2 days many different regions of the world have been struck by extreme weather and natural disasters. 

Has climate change played a role in these? 

There is evidence to support that climate change is playing a role in rainfall related extreme events. However, I did not think that climate change could play a role in seismic activity. Further research has found that, UCL Earth Sciences professor Bill Mcguire, has written a book 'Walking the giant: How a changing climate triggers earthquakes, tsunamis, and volcanoes', arguing that climate change has more of an impact on the Earths plate tectonic system than most modelling accounts for. He says:

"During this extraordinarily dynamic episode, as the immense ice sheets melted and colossal volumes of water were decanted back into the oceans, the pressures acting on the solid Earth also underwent massive change. In response, the crust bounced and bent, rocking our planet with a resurgence in volcanic activity, a proliferation of seismic shocks and burgeoning giant landslides."

Is our climate getting more extreme?

Our climate has rapidly changed since the 1950s, seeing more hot days and heatwaves

The clear message from the IPCC report: The Special Report On Managing Risks of Extreme Events and Disasters to Advanced Climate change Adaptation (SREX) is that with climate change will come increasing record- breaking temperatures, heat waves, and heavy rainfall events.

Figure 1: Implications of climate change on extreme weather
Source:https://www.carbonbrief.org/what-the-ipcc-report-says-about-extreme-weather-events

Below are some important findings that I have found from the report, however I would definitely encourage you to take a read yourself:

Warm and Cold nights

• "It is very likely that there has been a decrease in the number of cold days and nights, and an overall increase in the number of warm days and nights."
• "Abnormally hot days and warm nights and heat waves are very likely to become more frequent."
• "Cold days and nights are very likely to become less frequent"

Precipitation

• "There has been statistically significant trends in the number of heavy precipitation events in some regions. It is likely that more of these regions have experienced increases than decreases."
• "It is likely that the frequency of heavy precipitation will increase in the 21st century."
• "Heavy precipitation is projected to increase in some (but not all) regions with projected decreases of total precipitation (medium confidence)."

Cyclones

• "There is low confidence in any observed long- term (i.e.. 40 years or more) increases in tropical cyclone activity. It is likely that there has been a poleward shift in the main Northern and Southern Hemisphere extratropical storm tracks. There is low confidence in observed trends in small spatial- scale phenomena such as tornadoes and hail."
• "While it is likely that overall global frequency will either decrease or remain essentially unchanged, it is more likely than not that the frequency of the most intense storms will increase substantially in some ocean basins."
• "There is medium confidence that an increased anthropogenic forcing will lead to a reduction in the number of mid-latitude cyclones over each hemisphere, and there is also medium confidence in a poleward shift of the tropospheric storm tracks due to future anthropogenic forcings."

Droughts

• "There is a medium confidence that some regions of the world have experienced more intense and longer droughts, in particular Europe and West Africa, but in some regions droughts have become less frequent, less intense, or shorter"
• "There is medium confidence in a projected increase in duration and intensity of droughts in some regions of the world. Elsewhere there is overall low confidence because of insufficient agreement of projections of drought changes."

Floods

• "There is limited to medium evidence available to assess climate- driven observed changes in the magnitude and frequency of floods at regional scales. Furthermore, there is low confidence at the global scale regarding even the sign of these changes."
• "There is low confidence in projections of changes in fluvial floods."
• "There is medium confidence that projected increases in heavy rainfall would contribute to increases in rain- generated local flooding in some regions.

Below is a table taken from climate change 2013: The physical Science Basis

Figure 2: Projected impacts on extreme weather

Source: http://www.ipcc.ch/report/ar5/wg1/#.UlgAQ1CkoXc

Concluding thoughts 

The summary is very cautious with its findings and confidence levels, stating that " Extreme events are rare, which means there is limited data available to make assessments regarding changes in their frequency or intensity".  Generally, the report shows that some types of extreme weather will become more severe in the future, as the world gets warmer, although attributing any single extreme event to anthropogenic climate change is challenging. This type of overview is extremely important to planners, to prepare for an increase in extreme weather events, to try avoid a risk becoming a disaster.

While it is difficult to conclude that our climate is getting more extreme or not and whether this is due to anthropogenic warming to any degree of certainty. It is still possible to explore these varied changes in weather, and try to understand the possible causes behind these, which this blog will focus on in the coming weeks. 

Next week's blog will look at changes in precipitation and what this means in terms of climate change. 

Have a good and productive week.

Hurricane Matthew- Is this Climate change?

Hurricane Matthew- October 2016 

Figure 1: Definition of a hurricane

Source: http://oceanservice.noaa.gov/facts/hurricane.html

I am sure most of you reading this have read or seen in the news about Hurricane Matthew. The first I heard about Matthew was from my Nan, who rang from Jamaica, to tell us that a Category 5 hurricane was about to hit Jamaica. From the fear in her voice we knew it was more than just a bit of thunder, wind and rain that they were preparing themselves for. Luckily they escaped the worse of the impacts as it weakened, however it headed aggressively towards Haiti and the South- East coast (figure 2).

                                                                                  

Hurricane Matthew was a very powerful tropical cyclone, which set several records:

• The first Category 5 Atlantic Hurricane since Hurricane Felix in 2007. 
• The longest-lived category 4 (or higher) Atlantic hurricane in October
• The strongest storm to hit Haiti in 50 years, with the death toll being reported as over 1000.
• It joined the list of the top 10 deadliest hurricances
• And many more......

Figure 2: Path of Hurricane Matthew 

Source:http://www.nj.com/weather/index.ssf/2016/10/hurricane_matthew_questions_and_answers.html

Hurricanes and Climate Change

Hurricanes extract heat energy from the ocean and convert it to the power of the wind (figure 3), therefore the warmer the ocean, the stronger the hurricane will be, if all the other conditions it needs are met. Hurricanes generally occur over oceans when sea- surface temperatures (SSTs) exceed 26 ℃. Climate Change scientists are therefore confident that if we continue to heat up the oceans, we will see more Hurricanes like Matthew (Kossin, 2013).

Figure 3: The formation of hurricanes

Source:http://www.windows2universe.org/earth/Atmosphere/hurricane/formation.html

Studies have shown that while the amount of Hurricanes may slightly dip in the future, the most destructive ones will actually increase (Kang, 2015). Holland (2013) found that the proportion of Category 4 and 5 hurricanes has increased at a rate of ~25-30% per ℃ of global warming (figure 4). The message being put forward is that hurricanes that do occur in the future will be stronger and will intensify a lot quicker. But is this due to anthropogenic climate change?

Matthew remained a category 4-5 hurricane for 102 hours. This is the longest amount of time on record that a hurricane of this strength has persisted in the Atlantic Ocean during October. This is an indicator of climate change increasing powerful hurricanes, not only the frequency, but they are occurring in months that do not usually support tropical storms of this strength, due to warmer waters. Furthermore a prolonged length of the hurricane season has been observed- this has been increasing since 1995, which is one of the big signals of the impacts of climate change (Huffington post, 2016).

figure 4: Hurricane 1-2 category events decreasing and hurricane 4-5 events increasing - with temperature

Source: http://link.springer.com/article/10.1007/s00382-013-1713-0

What we do know for sure, is that Global warming is causing sea level rise which makes storm surges more destructive- meaning that Hurricanes such as Matthew are creating more damage, than they may have otherwise. Higher sea levels, give coastal storm surges a higher starting point when major storms approach the shore. The storm surge which is created therefore, reaches higher and penetrates further inland. This increases the risk of flooding and landslides.

What does the future hold?

As global temperatures increase, the frequency of intense category 4-5 hurricanes in the North Atlantic is projected to increase. However, the overall number of hurricanes globally is expected to either decline or remain unchanged (Bender, 2010).

Models by Emanuel (2013) suggest that under the RCP8.5 emissions pathway, the power dissipation will increase by 45% by 2100, with a 40% global increase in category 3-5 hurricanes. Bender (2010) produced very similar model projections, which projects that the frequency of category 4-5 storms increasing by 50% in the Atlantic by 2100. There are however disputes over whether the total frequency of tropical storms will increase in the future. Emanuel (2013) suggests that by the end of 2100 there will be substantial increases in tropical cyclones. However, in agreement with Bender (2010), Knutson (2010) concluded that the mean global frequency in tropical cyclones will decrease from 6- 34% by 2100.

There is however only limited evidence to suggest that these past and projected changes are due to anthropogenic warming.

Next week's blog will look at the main findings from the IPCC report on extreme events and climate change.

Introduction: Extreme Weather and Climate Change

Welcome!

Hi and welcome to my new blog 'Extreme Weather: The Deadly consequences of Climate change?'

This blog is part of my third 3rd year Geography module 'Global Environmental Change'. This is my second blog that I have started this academic term, the first one was for my other module 'Water and Development in Africa', in which I will post weekly about the complex relationship between water and environmental change in Africa. That blog has quite a few cross overs with this one, You should take a look. The first blog, provides an important overview, in how extreme rainfall will become more extreme due to increasing temperatures.

This will also be a weekly blog, where I will be exploring the complex relationship between Extreme Weather and climate Change. A vast array of topics will be covered using academic reports, news articles, books, and videos to explore this topic further. I chose extreme weather, because this is where my interests lie, as i want to get into disaster management of some sort, especially with climate change, projected to intensify these events. 

My interest for natural hazards stem from a 9-week holiday in Grenada visiting my grandparents in the summer of 2005. July 14th, hurricane Emily hit which was quite devastatingly early into the holiday. This has got to be probably one of the fondest memories I have with my grandparents.... I remember it so vividly, just seeing the power of nature, and everyone's life- their homes, their livelihoods, everything they owned- just rolling across the roads with the wind and rain. Watching the devastation around us from a window, it was very surreal.

Figure 1: Path of Hurricane Emily 2004, Eastern Caribbean, Grenada

Source: http://www.trinidadandtobagonews.com/forum/webbbs_config.pl?md=read;id=3010

This blog therefore is a great opportunity to explore my interests further, and share what I find you all.

Climate Change

The world is getting warmer- Over the past 30 years there has been a trend of increasingly higher average temperatures.

The purpose of the intergovernmental Panel on Climate Change (IPCC) is to evaluate the state of climate science as a basis for informed policy action, primarily on the basis of peer- reviewed and published scientific literature (Oreskes, 2004). In its Climate change 2014 report, the IPCC states that the scientific consensus is that Earth climate is warming due to human causes.

Figure 2: Observed Global Climate change and its causes taken from the IPCC 2014 summary for policy makers

Source: https://www.ipcc.ch/pdf/assessment-report/ar5/syr/AR5_SYR_FINAL_SPM.pdf

Climate change has widespread implications. Changes in extreme weather and climate events have been observed since about 1950.  According to the IPCC some of these changes have been linked to anthropogenic influences.

Extreme weather and climate change

Extreme weather and climate events are events that:

• Don't happen frequently 
• Vary from the 'norm' in severity or duration
• Have severe impacts

With climate change scientists expect many changes in extreme weather events these include:

• Extreme weather events occurring more frequently than they did in the past
• Events becoming more intense, with the potential to create more damage
• Events lasting long than the 'norm'
• Events occurring at different times of the year ie. earlier or later in the season or year than they used to.

Figure 3: The strength of evidence for human induced climate change causing extreme events

Source: http://www.ucsusa.org/global_warming/science_and_impacts/impacts/extreme-weather-climate-change.html#.WCjMq3d0dmB

Strong scientific evidence links climate change with heat waves and coastal flooding. Other forms of extreme weather have been closely linked with climate change, such as extreme precipitation events in some areas and severe droughts in others. There is however limited evidence and confidence from observed data that Tornadoes and Hurricanes are caused by climate change (figure 3). However this is an active area of research, where there is a strong scientific consensus that increasing temperatures will increase the severity, not necessarily the amount of these events.

Solomon et al, (2007) Bell curve

Figure 4: Solomon et al, (2007) Bell curve- increase in temperature means increase occurrence of extreme weather

Source: https://www.epa.gov/climate-change-science/understanding-link-between-climate-change-and-extreme-weather

Watch the Extreme Weather Bell Curve Animation

Weather variation can be described with a rough bell- shaped curve (figure 4). A small increase in average temperature leads to vast changes in weather: A changing climate leads to changes in the frequency, intensity, spatial intent, duration and timing of extreme weather and climate events.

Will extreme weather become the new normal?

Typically, extreme weather is very rare, however with climate change, the odds of an extreme weather event taking place is increasingly higher, and likely to be even more extreme.

Even if we dramatically curb emissions, extreme weather will be apart of our future. Therefore, we must adapt to the likelihood that extreme weather events are becoming ever more commonplace. Smart planning and engineering solutions will need to be developed to cope with this obstacle, especially for the most vulnerable.

Next week's post will look at Hurricane Matthew and discuss the possibility if climate change played a role in the extremity of this event.