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.