Revisiting the evidence on climate change

It’s 73 degrees in Ithaca, New York today, according to the thermometer on my minivan. My 7-year-old begged to wear shorts to school today, and soon thereafter reminded me, “It’s still winter mom!”  Given such an early spring-feeling day in this northern latitude, I thought it’d be a good time to revisit the evidence on global warming.

(We’ve written about various aspects of the topic before, including the broad body of evidence supporting climate change, actions humans can take to slow climate change, the ways in which Americans perceive climate change, and a new way to frame climate change that focuses on public health.)

Let me begin today by saying that the evidence is clear that single warm days, or even warm spells, are not a direct result of climate change.  But an unusually warm day in early March did get me thinking about the broader problem of global warming. So I went looking for new evidence.

I found a fascinating web site published by NASA that clearly lays out the evidence surrounding the causes and consequences of climate change.

The web site documents a dramatic rise in carbon dioxide levels in the atmosphere, which have continued to skyrocket past previous high levels beginning in the 1950s. Today, we have the highest levels of carbon dioxide documented in the atmosphere in at least 400,000 years.

There is also substantial evidence that sea levels are rising twice as fast as they have over the past century, while the ice sheets in Antarctica and Greenland have shrunk significantly, and mountain glaciers across the world have retreated.

Snow in the Northern Hemisphere is melting earlier each year, and spring snow cover has decreased, according to satellite images.

And the oceans are both warming and becoming more acidic. The top 2,300 feet of ocean has warmed a third of a degree Fahrenheit since 1969, a change that affects ocean life and weather patterns. The acidity of surface ocean waters has increased by about 30 percent as well, a change that has a ripple effect throughout the marine food chain and impacts the overall structure of marine ecosystems.

As I sit here in my shorts and t-shirt in early March, the take-home message is clear: There is a strong, persuasive body of evidence that our global climate is changing, and it will have a far-reaching impact on the Earth as we know it.

In tandem with the NASA web site, the U.S. Environmental Protection Agency published a web site that includes small changes anyone can make that will help slow climate change.  The list is long and includes many action items you would suspect such as changing to Energy Star light bulbs and appliances, recycling, insulating your home, using public transportation and performing regular maintenance on your car.

Given the irrefutable evidence that climate change is happening, it’s certainly worthwhile to make some personal changes that will help to solve the problem.