What feels like an abnormally cool May in the Washington, DC area might just make us forget about the record warm temperatures in the past six months, and have us longing for some spring-like weather. But NASA will not let us of the hook, and sure enough, April was another whopper of a record-breaker: It was 1.11ºC (just about 2ºF) above the average April temperature for 1951-1980. This new record is 0.24ºC (0.43ºF) higher than the previous April one, set in 2010.
NASA data show that seven months in a row have been warmer than average
The news of the seventh month in a row with temperatures at least 1ºC above average comes on the heels of the announcement that CO2 levels in the Southern hemisphere have for the first time surpassed the 400 parts per million (ppm) symbolic benchmark for CO2 concentration in the atmosphere. (In the Northern hemisphere that mark was reached 3 years ago in May as well, when concentrations tend to peak.)
2015 saw the highest annual growth rate in CO2 concentration, or “the largest year-to-year increase in 56 years of research” according to the World Meteorological Organization.
CO2 concentration per year. Graphic: Climate Central
Warmer climate may affect the severity and extent of extreme events
With global warming, the ranges of temperatures in different regions may be very different, and lots of natural processes depend on those ranges. Those include physical, chemical, and biological processes.
I wrote about phenological traits last month, and the recent worst-ever coral bleaching in Australia and wildfires in Alberta are other examples of what can happen when temperatures steadily go up. Global warming makes for warmer seawater, which can effectively reduce protective measures used by corals when dealing with warmer waters.
Climate change also increases the risk of wildfires due to hotter and drier conditions. A recent study found that projected climatic changes can lead to an increased fire risk in areas where fires historically have not been common, such as tundra and boreal forests in Alaska.
The consequences and costs of dealing with these fires, which occur many times near populated areas, can be staggering. Northern forests are also seeing changed tree dynamics and species-specific declines and changes in forest composition due to climate change-induced induced insect damage.
Flooding events also carry the signature of climate change
US states with biggest increases in downpours. Graphic: Climate Central
Heavy downpours are on the rise in the US, for the straightforward reason that with global warming, air is warmer, and warmer air can hold more water vapor.
Changes in storm patterns, influenced by climate change, also play a role. A recent study stated that “extreme precipitation intensity is expected to increase in proportion to the water-holding capacity of the atmosphere,” but suggests that storm patterns are also changing since the observed increases in precipitation are larger than expected based simply on the water amounts in the atmosphere.
Many states are seeing these increases in heavy downpours, and the associated risk of flood cannot be ignored.
In the US, this is especially true in the Midwest and the Northeast, but other areas are also seeing a pattern of increased heavy rain. Of course Houston comes to mind, since it recently was slammed by more than 16 inches of rain in less than 24 hours.
With El Niño still in action, the storm systems have had a lot of excess moisture along the Southern states—we can say the storms were “turbocharged.”
Even in the absence of El Niño, however, there is an observed change in very heavy precipitation for the area that includes Texas, Oklahoma, and Kansas (called the Great Plains South in the National Climate Assessment). Houston itself has seen a 167 percent increase in heavy downpours since the 1950s.
Change in very heavy precipitation in Texas, Oklahoma, and Kansas. Graphic: National Climate Assessment
The effects on property and life have been devastating, and cause for great concern – will these events occur more often, and will they be as severe? How can we prepare? What can be done?
Preparedness and mitigation must go hand in hand
While all these events carry the signature of climate change, it is important to note that measures taken now, such as a shift to renewable energy and a reduction of emissions from burning coal, oil, and gas, can help reduce this signature and slow down global warming.
Yes, there are problems such as wildfires and floods, and we see them, and while preparing for them we must also be focusing on the solutions, as stated in a recent NASA blog.
The signs that good things are happening on the renewable energy front are very encouraging, and honestly, surprising for many a skeptic who said we couldn’t effect change with the current renewable technology. Well, looks like change is here.
Featured image: Austin Marshall/CC-BY (Flickr)