One of the mantras of climate change denial is that the Earth is no longer warming, as repeated in a recent Missoulian letter. Deniers also glibly cry "hoax!" whenever we hit a particularly cold period, such as lampooned in recent editorial cartoons.
To the first point: after steadily rising for over two decades—clearly correlated with rising atmospheric CO2 and human-caused carbon emissions—the average global temperature suddenly spiked in 1998 and has been relatively flat since. This is the source of deniers claiming global warming has stopped. However, it’s also true that this peak year was slightly surpassed in 2005, then topped again in 2010, and that the last 13 years lie in the top 14 warmest years in modern records (1998 being the 14th). Climate scientists call this sustained warm stretch a pause or plateau, expected to be temporary as the oceans reach their limit of absorbing much of our excess carbon dioxide.
An analogy might be: in the midst of a record-breaking July heat wave, we don’t break the Missoula record of 107 every day, but the 100-degree days go on and on and on. A denier would say, “So what? We didn't hit 108 today.”
The wintertime cries of hoax remind me of a Stephen Colbert joke. To paraphrase: “Global warming? What global warming? It’s cold outside! Why, I’ve heard talk of global hunger as well. Really? I just ate!”
Climate scientists have just announced that 2014 is on track to easily break the 2010 record for average global warmth—despite last winter’s string of polar vortices that hit the U.S. and the most recent cold spell.
That’s why it’s called global.
November marked the 357th consecutive month with a global average temperature above the 20th century average.