Global Warming: Even Half Degrees Matter

Since pre-industrial times, human activities have caused approximately 1 degree Celsius of global warming—at the current rate, that figure will rise to 1.5 Celsius as soon as 2030. This is the basis of last fall’s UN Special Report, issued by the Intergovernmental Panel on Climate Change. Natalie M. Mahowald PhD '96, a professor at Cornell University, contributed to the report as one of 91 authors from 40 countries who came together to think about climate change in the context of sustainable development and global efforts to eradicate poverty.

Mahowald shared insights into the report and its outcomes during a recent installment of the MIT Alumni Association’s Faculty Forum Online, Alumni Edition.

In this video, Mahowald talks about the potential changes and risk factors associated with global warming and how important it is to limit the warming as much as possible.

“We in the scientific community started to look at how much does a half a degree matter,” explains Mahowald.  “1.5 versus 2 sounds small. Can we actually tell the difference? It turns out, yes, you can tell the difference—it’s statistically significant. If we can keep the warming to 1.5 versus 2 degrees, there will be less extreme weather, less extreme heat and rainfall, and it would lower the global mean sea level rise about 10 cm.”

The talk was moderated by Susan Phillips, energy and environment reporter for NPR and a 2014–15 MIT Knight Science Journalism Fellow.

Watch the video above, then catch up on previous talks from the Faculty Forum Online.

Want more on this topic? You can also visit the MIT Climate portal to hear a new podcast featuring MIT civil and environmental engineering professor Elfatih Eltahir SCD ’93, SM ’93, who reviews the effects of climate change around the world, from malaria in Africa to heat waves in Southern Asia.