It’s unequivocal. From rising temperatures and sea levels to melting sea ice, glaciers and ice sheets, the evidence is overwhelming. The Earth is warming. Yet, in the U.S. many remain skeptical of the science behind global warming, and even if they acknowledge that the Earth is warming, they attribute it to natural causes.
We’ve all heard the adage that a picture is worth a thousand words. If you have any doubts about warming, take a look at a graphic compiled by Professor Ed Hawkins at the University of Reading in the UK. First a few words of explanation. If you click on the graphic, you’ll see three red circles on a dark background. The radius of each circle is a measure of the amount by which the Earth’s temperature ‒ measured in degrees centigrade ‒ exceeds a baseline value for the year 1850. The outer circle corresponds to an increase in temperature (2ºC) that is commonly viewed as a benchmark above which the effects of warming would be serious and potentially unmanageable. The intermediate circle reflects growing concerns that 1.5ºC may be a more appropriate benchmark, and the inner 0ºC circle characterizes the 1850 baseline.
Now note months of the year marked just as 5-minute intervals would appear on the face of the clock. Click on the arrow, and you will track the progression of monthly temperatures from 1850 through March of this year. Despite fluctuations from month to month, the overall trend is one of temperatures spiraling upward and approaching the first threshold of 1.5ºC.
Yes, warming is real, and if you’re not concerned, you should be. But, perhaps you’re not concerned because you believe that the warming is due to natural causes and that current trends may well be reversed by natural variability. If so, I invite you to look at a sequence of graphics compiled by the Bloomberg Company.
The graphics show the increase in the Earth’s average surface temperature from 1880 through 2014 and then compare it with results predicted by a model developed by NASA’s Goddard Institute of Space Studies. The model separately addresses the influence of natural factors (the temperature of the Sun, parameters associated with the Earth’s orbit about the Sun, and volcanic activity) and human factors (deforestation and accumulation of ozone, aerosols and greenhouse gases in the atmosphere). The results are conclusive. Warming is due to human activities and attributable largely to greenhouse gases produced by the use of fossil fuels.
The bottom line is that we have a serious problem of our own making, and it must be addressed. What can each of us do to reduce our own greenhouse gas emissions? What can we do to support other efforts to reduce emissions ‒ through our organizations, churches, and political bodies?