If higher carbon dioxide warms, earth's climate history makes sense, with carbon dioxide having caused or amplified the main changes.
If carbon dioxide does not warm, we must explain how radiation physicists are so wrong and how a lot of really inexplicable events happened over earth's history.
The argument deniers make is what's called a logical fallacy: If the data shows that temperature does not track CO2, then CO2 must not be responsible for warming the Earth's climate. Correct logic: CO2 is the only validated explanation of trapping warmth on the Earth, yet sometimes there are variability in the correlation between CO2 and temps, therefore other factors must be diminishing the effects. What we're learning now is the release of pollution and particulates into the air has a cooling effect often called "global dimming." As we get better about cleaning up pollution, which is a good thing because of the negative health effects, we're actually going to remove the dimming factors too. In other words, increases in temperature have been artificially muffled...so the warming is going to be a lot worse than we actually thought because of global dimming.
We're running out of time. The Earth is going to be fine. As George Carlin says, it's the people that are fucked.
It happens every year and it seems to be getting worse. We get a big snowstorm on a major metropolitan area and all the sudden people start pointing their finger at Al Gore. "It's snowing, so surely global warming must be a farce designed to make Al Gore rich, poison your kids, bankrupt our governments and turn America into a haven for socialistic gay-sex-and-abortions-for-all loving hippies."
The wrong wing loves to gloat when we get a lot of snow. To be fair, for the average layperson (emphasis added) there is a very slightly counter-intuitive notion about having a warming climate yet seeing more snow. So here's a basic lesson that I am sad to have to explain again this year: weather is what happens next weekend in Chicago, climate is what happens over a long period of time covering a large area. Saying that global warming doesn't exist because we get a lot of snow, or even many many bad snow storms, is like saying that diet and exercise doesn't work because I ran for an hour and I still have a fat ass.
But don't take my word for it, listen to what scientists are getting tired of repeating year after year (from Discovery):
I'm not saying anything new here, but the whole idea behind climate change is that it's happening to the entire planet. It takes years, even decades to move the needle on Earth's climate. Meanwhile, heat waves, cold snaps, droughts, and snowstorms come and go. As this piece in Time points out "Weather is what will happen next weekend; climate is what will happen over the next decades and centuries." Again, old news.
And yet, we routinely conflate current and near-term weather conditions with what's happening to the global climate. It's exactly the wrong thing to do, and yet we do it every day. Why? Because, let's be honest, everyone enjoys complaining about the weather.
That's completely fine: getting frustrated about something that is utterly out of your control and can ruin your day makes sense -- like a mysterious charge on your credit card bill, say.
But statements about fickle weather have little place in the discussion about large-scale climate change. Studies do suggest more stormy weather is possible as the atmosphere becomes supercharged with moisture due to global warming. And if parsed just right, good arguments can be made that explain short-term weather in context of long-term climate records.
So if you want to have a rational fact based conversation about why we're having all this wacky weather, here are a few key points that scientists keep saying again and again:
The past decade was the warmest on record and that the Earth has been growing warmer over the last 50 years (source: More than 300 scientists from 160 research groups in 48 countries contributed to this NOAA report)
Analysis of global surface temperatures by NASA scientists finds 2009 was tied for the second warmest since 1880. In the Southern Hemisphere, 2009 was the warmest year on record. (source: NASA, and this is despite the crazy weather from El Nino)
Global precipitation in 2010 was well above the 1961–1990 average, ranking as the wettest on record since 1900. (source)
Rising Arctic temperatures have reduced floating ice cover by 20 percent over the last three decades.
December 2010 had the lowest ice extent for the month since the beginning of satellite records. The linear rate of decline for the month is –3.5% per decade. (source NSIDC)
This past year the arctic had the warmest waters they've had in the past 2000 years, and the scientists who wrote the study add: "On a scale of 2,000 years, it stands out dramatically as something that does not look natural."
To break it down even further, when we stop complaining about the weather we can begin to explain the wacky weather using science. A warmer global temperature means more water exists on Earth as water vapor, which means more and more severe precipitation. Not that complicated is it? Here's another interesting part which explains why all these wacky effects are compounded even further:
Counterintuitive but true, say scientists: a string of freezing European winters scattered over the last decade has been driven in large part by global warming.
The culprit, according to a new study, is the Arctic's receding surface ice, which at current rates of decline could disappear entirely during summer months by century's end.
The mechanism uncovered triples the chances that future winters in Europe and north Asia will be similarly inclement, the study reports.
The only thing finger we should be pointing at Al Gore is that he should not have called it global warming (even though that's what's happening), it should be called climate change. Because so many people don't know that there's a difference between weather and climate.
