I came across a startling quote the other day, and I just had to investigate. Grist.org wrote:
“If you’re 27 or younger, you’ve never experienced a colder than average month.”
Astonishing! Could that really be true? Being in the aforementioned demographic, I decided to find out.
Take a look at the graphic Grist shares detailing temperatures thus far in 2012:
This map, provided by NOAA, illustrates how this year’s average temperatures around the world stack up to historical data. As you can see, this year (so far) has been warmer than average – or at least near average – on every land surface except western Alaska and eastern Russia (large swaths over the Pacific Ocean have actually been cooler than average). This image likely comes as no surprise to most, given the exceptionally hot and dry summer experienced here in the United States.
In reference to October 2012, NOAA says:
The average temperature across the land and ocean surfaces during October was 14.63°C (58.23°F). This is 0.63°C (1.13°F) above the 20th century average and ties with 2008 as the fifth warmest October on record. The record warmest October occurred in 2003 and the record coldest October occurred in 1912. This is the 332nd consecutive month with an above average temperature.
332 months is 27.67 years, so that’s where the quoted figure comes from. But what may not be as obvious is that the temperatures being talked about here are global averages. Worldwide, we have been steadily seeing warmer than average temperatures since April of 1985, but that doesn’t mean that individual countries or regions haven’t seen colder than average temperatures during that time.
I did some digging in NOAA’s National Climatic Data Center (check it out here – they have oodles of interesting data), and I discovered that, since 2000, the U.S. actually had colder than average October temperatures in 2002, 2006, and 2009. Here in Virginia, we had colder than average Octobers in 2001, 2003, 2006, 2008, and 2009. [Side bar: Has your state or country seen cooler than average October temps since 2000? I’d love to hear about it in the comments!]
So, it looks like that quote is a bit misleading. Depending on where you live, you may very well have experienced a month that’s colder than average – I certainly have. But Grist’s statement is still powerfully important because it reveals that, globally, temperatures are rising. To have gone more than 27 years (332 months) without seeing cooler than average global temperatures would be incredibly unlikely, statistically speaking, unless the Earth’s climate really were warming.
Considering the odds, I think the wisest decision is to assume this data accurately reflects a changing climate and adjust our actions accordingly. (And as someone who loves winter sports, here’s hoping for a cooler than average winter!)