From the moment a powerful blizzard hit the northeastern United States — only a few weeks after comfortable, spring-like weather — the questions about climate change's impact have been asked.
According to leading scientists, we bear some responsibility for the storm, which covered much of the inland areas with up to two feet of snow. And President Donald Trump is definitely not helping matters.
"There is a connection between global warming and the increased frequency of heavy snowstorms," said James Hansen, a professor of Earth and Environmental Sciences at Columbia University. "One factor is the increased amount of water vapor that the atmosphere holds in a warmer world." In the late 1980s, Hansen testified that climate change — and the warming of the atmosphere — leads to "greater heat waves and stronger droughts" but more rain and floods in areas.
"The '100-year flood' now occurs more often than once a century," Hansen said.
Michael E. Mann, Director of the Earth System Science Center and Distinguished Professor of Meteorology at Penn State University, observed that the warming climate is actually causing more snow. "The oceans have been at record levels of warm the past two years (and climate change is a key contributor to that)," Mann said. "That record warmth means that there is more moisture in the atmosphere that is available both to help strengthen the storm and produce record snowfalls as the warm oceanic air is entrained in toward the eastern U.S. by the cyclonic winds of the storm. Climate model simulations indicate a likelihood for stronger, more snow-making storms, and that’s what we’re seeing."
Naturally, climate change deniers like to joke about how the Earth couldn't be getting warmer if we're seeing colder weather.
"It is quite wrong to associate snow with cold," said Kevin Trenberth, who works for the Climate Analysis Section at the U.S. National Center for Atmospheric Research. "On the contrary, we expect more snow in mid winter with global warming and this is what is observed. The snowpack across the Northern Hemisphere has increased from November to February. But it is much less from March to September. The snow season is shorter at each end and snow melts more rapidly."
But the warmer climate is also leading to problems in the Arctic — and colder weather for the U.S. at the same time.
"The warming of the Arctic reduces the temperature gradient from middle latitudes to the pole," Hansen said. "A strong temperature gradient tends to make for a strong, tightly-wound tropospheric jet stream — and a strong tight jet stream helps to limit the outbreaks of cold polar air into midlatitudes. The warming of the Arctic, which was predicted by all global climate models, has caused the jet stream to be weaker, more 'waggly,' allowing more cold air outbreaks. Because of conservation of mass, these are accompanied by warm air outbreaks into the Arctic — a few of these were reported this winter, with the Arctic being 20-30 degrees warmer than normal."
There's worry that the world is reaching the point of no return, which is the worst time for the government to turn a blind eye.
"Trump and the Congressional Republicans are damaging so many American institutions and social norms, it is hard to see their egregious stance towards climate change as among the most dangerous of their actions," wrote Ken Caldeira from the Department of Global Ecology at the Carnegie Institute for Science. "Their stance towards climate change is consistent with the rest of their actions: 1. Promote 'get-richer-quicker' schemes for a select few even if that means deteriorating conditions for the average person. 2. Promote ignorance and disinformation when facts get in the way of 'get-richer-quicker' schemes. Distract and confuse with anecdotal stories that promote intolerance and discriminatory practices."
Here's the real danger of climate change — warmer waters could mess everything up, causing worse weather to become the norm.
"Global warming is already causing the Atlantic Meridional Overturning Circulation (AMOC) to begin to shut down," Hansen said. "That ocean circulation (which includes the Gulf Stream) carries heat north. Therefore the circulation slowdown is causing ocean heat to pile up along the eastern seaboard, where the ocean surface is now significantly (a few degrees Celsius, at least 5 degrees Fahrenheit) warmer than normal. This warm ocean provides moisture that allows for huge snowfall events, which occur when we get one of those cold air outbreaks from Canada."