Extreme Weather and Climate: Ever the twain shall meet
At the end of the first week in November, typhoon Haiyan, one of the worst ever, hit the Philippines leaving over 4,000 dead, and 4 million displaced and in desperate need of food, water, and medical assistance. Ten days later, between 40 and 80 tornadoes struck 12 mid-western US states, leveling towns and causing as much a $1 billion damages. Five days later Sardinia, Italy was inundated with 17 inches of rain over a 24-hour period killing 16 and destroying roads, railways, power and telecommunication lines.
Is there something behind these extreme events?
The recently released Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change, “Summary for Policymakers”, concludes:
Changes in many extreme weather and climate events have been observed since about 1950 … It is very likely that the number of cold days and nights has decreased and the number of warm days and nights has increased on the global scale. It is likely that the frequency of heat waves has increased in large parts of Europe, Asia and Australia. There are likely more land regions where the number of heavy precipitation events has increased than where it has decreased. The frequency or intensity of heavy precipitation events has likely increased in North America and Europe. In other continents, confidence in changes in heavy precipitation events is at most medium…[minus cites].
While extreme precipitation is more likely to occur, the IPCC reckons that the frequency of cyclones will stay the same or decrease but their average intensity will go up. The effects of climate change on cyclones, tornadoes, and hurricanes is very complicated and the confidence in predicting the impacts of climate change on these storms is less than for other extreme weather events.
There have been recent studies suggesting that extreme weather events, including hurricanes and cyclones, may have more to do with the general public’s growing acceptance of the reality and risks of climate change than any scientific evidence or entreaties by environmentalists. So it is a bit ironic that the “evidence” which the scientific community has less confidence in is more persuasive with the general public.
Whatever uncertainties remain about cyclones and tornadoes, extreme weather events are heading our way and we had better prepare for them or get out of the way, as the IPCC AR5 makes clear.
In light of the highly technical nature of the IPCC reports, and their critical role in explaining the risks from climate change, there are many scientists, individually and collectively, working very hard to condense and translate the data and conclusions for a wider, non-science public. In one such venture, the New School for Social Research in New York City convened a panel of experts to try to tease out the findings and implications of the IPCC report on our understanding of the nature and impacts of extreme weather events. Last year’s extreme weather event a/k/a Sandy continues to focus minds in the New York area on climate change and extreme weather.
One of the speakers, Robert Kopp of Rutgers University, focused on the actual impacts of climate change and extreme weather. As he noted, climate addresses changes in means while weather addresses variability, and that when we think about damages from extreme events, we have to think about the interaction between variability (weather) and changes in the mean (climate). In the IPCC scenario, RCP 8.5, or business-as-usual, it is very likely that there will be a global warming of 3-7°C [5-13°F] by 2100 above pre-industrial levels. But, Kopp pointed out, nobody lives at the global means, so local impacts have to be separated out — we need to look past the mean. For instance, land warms faster and oceans warm slower than the global mean, and the Arctic is warming twice as fast as the global mean.
Looking at more local changes, in New York City, the changes in temperature extremes of days above 90°F will go from 18 days/year in 1971-2000 to 24-33 days in 2020s and 32-57 days by 2050s; and days below freezing will fall from 72 in 1971-2000 to 50-60 days in 2020s and 37-48 days in 2050s. With higher summer temperatures, there will be increased demand on electricity, from air conditioners, at the same time there will be less water runoff which in turn will reduce water supplies for power plants.
As we learned from Hurricane Sandy, the energy infrastructure is most vulnerable. In New York, that infrastructure was largely the result of Thomas Edison locating power supply and the energy grid near the big industrial users which were drawn to water bodies for the supply of water. Only now are we accepting the need to relocate that infrastructure, and the costs are considerable. At least we in developed communities have the resources to pay for many of the costs.
In any analysis of local impacts, socio-economic dimensions need to be recognized, including the common sense reality that wealthier people cope better than others with extreme events, with the corollary that wealthier nations will likely do better at adapting than developing countries.
Kopp ended with a point that often gets lost: climate change does not end in 2100. If we proceed with business-as-usual, some of the worst predictions put temperature rises at 11°C [20°F] by 2200. The current maximum temperature has been estimated at 35°C, and our body temperature is 37°C. At the higher temperatures by 2200, and without air conditioning, we will not be able to cool ourselves by sweating, with deadly consequences.
At the end of the talks by three speakers, Michael Oppenheimer, of Princeton University and a seminal figure in the history of the IPCC, was asked to comment. Among other comments, Oppenheimer reasoned that just with what resources we have and what we know now, we are not able to cope with extreme weather events; while we may lessen, we cannot stop the damages and deaths they cause. How do we expect to cope with the greater events that climate change is producing.
IPCC, 2013: Summary for Policymakers. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
David Biello, “What Role Does Climate Change Play in Tornadoes?” Scientific American (21 may 2013). www.scientificamerican.com/article.cfm?id=kevin-trenberth-on-climate-change-and-tornadoes
The Global Warming Policy Foundation, “The IPCC on Cyclones and Typhoons” (12 Nov 2013). www.thegwpf.org/ipcc-cyclones-typhoons/
Local and Global Impacts of Climate Change, The New School for Social Research, New York, NY (18 November 2013). new.livestream.com/TheNewSchool/econofclimatechange/videos/35154177
Peter Schlosser ,Professor of Earth and Environmental Sciences, Columbia University; Deputy Director and Director of Research, The Earth Institute at Columbia University.
Robert Kopp, Assistant Professor, Department of Earth & Planetary Sciences, Rutgers University; Associate Director, Rutgers Energy Institute. Kopp’s talk starts at minute 30:20 and ends at 54:30
Wolfram Schlenker, Associate Professor, School of International and Public Affairs, Columbia University.
Oppenheimer’s remarks follow Schlenker’s talk.
Climate Communication: Science and Outreach, “Current Extreme Weather & Climate Change.” www.climatecommunication.org/new/articles/extreme-weather/overview/
Emily Swanson, “Americans Are Convinced Climate Change Is Connected To Stronger Storms, Poll Says” Huffington Post Green (22 Nov 2013). www.huffingtonpost.com/2013/11/22/climate-change-poll_n_4319485.html?utm_hp_ref=green
Lynne Peeples, “Oklahoma Tornado’s Climate Change Connection Is ‘A Damn Difficult Thing To Predict’” Huffington Post Green (21 May 2013; updated 22 May 2013). www.huffingtonpost.com/2013/05/21/oklahoma-tornado-climate-change_n_3310413.html