It’s been three months since my first Global Climate Snapshot, and it’s time for an updated look at the many forms of official data concerning our planet. Many skeptics distrust the official data about some things for one reason or another, but let’s assume it’s real and see what it says. When I analyze data about the earth’s climate, I look for two things to help judge whether or not it points to (man-made) global warming: 1) Are we reaching new records? 2) Are we reaching them as fast as scientists have predicted?
Oceans and Ice
The northern ice cap had its best spring in a decade, but all that extra ice has melted, and the sea ice is currently flirting with the record low years of 2007 and 2011. So far, NO, the cap is not retreating to new records. After the record low of 2007, some predicted the ice might be gone entirely by this summer. But not only will the ice not disappear entirely, it may not even be any smaller at all. It doesn’t look strong, though, and it is very possible we will see a new low this year.
Meanwhile, the Antarctic ice cap continues to grow above average as it heads toward its winter maximum. The reports that the ice is melting underneath have still not led to evidence in the surface data. Instead we continue to see increases in Antarctic sea ice, which I interpret as NO evidence of warming. There have been headlines about ice on Antarctica melting into the ocean, which could lead to above average sea ice, but if that’s happening, it should show up in the sea level data…
Three months ago the sea level data had stagnated for two years. We have seen a new record high since then, which indicates that YES things are at least moving in the direction predicted by global warming. However, the current rate of 3.1mm/year is nowhere near the increase needed to meet projections of 1m or more by 2100, because that would only get us to 0.31m. It’s supposed to accelerate, but based on my crude attempt at creating an exponential graph that matches the low end of the IPCC projections, it should already be moving by at least 5mm/year, and we might already be over 10mm behind. I’ll have to look at this more rigorously later, but it looks like NO the sea level is not rising nearly as fast as has been predicted.
According to the temperature data, the contiguous US is having its warmest year on record by quite a bit, although Alaska (which is half as big) is having its 16th coolest year. Still, there have been a lot of broken records in the lower 48 states this year, and YES it does look (and feel!) like a warming planet.
The global data, though, is less convincing – and after all, it’s the global data that matters most. The planet is currently having its 11th warmest year on record. The overall data continues to look flat since 1998, and is certainly not accelerating. I’m going to say that for now NO it does not look like a warming planet, although the anomalies have increased throughout this year as La Niña fades, and there’s still plenty of room for more warmth. But we’re supposed to get at least 2 degrees of warming this century, and we still have essentially 0.
The drought in the US is the worst since the Drought Monitor started in 2000, with over 80% of the contiguous US in some form of drought category. Many are saying it’s the worst drought since 1988 (that’s the big blue dip on the right half of the above precipitation graph, which shows a 2012 that so far is low but by no means unusual). The drought is hurting crop yields, and corn and wheat are nearing or hitting record prices, but that’s more due to increased demand; global corn output is still expected to be the second-largest ever this year. So this is a fairly rare level of drought, but it’s not even worse than 1988 yet, and certainly not worse than multiple heavy droughts of the 1930’s. I don’t think the 2012 drought is evidence that droughts have become more common, so NO it does not look like global warming. At least not yet.
Tornadoes started above average this year, but almost disappeared with the lack of rainfall in the summer, and the year-to-date is now in the bottom quartile of the records. Last year was the strongest year for tornadoes since 1974, ending a long stretch of relatively low tornado activity. With only 26 F3 or greater tornadoes so far this year, and the worst months of tornado season behind us, it continues to look like there’s absolutely NO increasing trend in tornadoes.
Atlantic hurricanes. This year’s Atlantic activity started with a bang; two storms were named before the official June start of the season for the first time since 1908, and four storms before July for the first time on record. But unless something changes quickly – and there’s nothing on the horizon right now – the month of July will have no hurricanes at all. By this point the record season of 2005 was already through G; we’re still on D. The next three months are typically stronger for hurricanes, though, so anything could happen. Overall, though, I don’t think the average number of hurricanes has increased since the 1930’s (though we have at least identified more tropical storms since the 1990’s, but we probably missed those smaller storms in the past). So NO it doesn’t look like global warming. If we break the 2005 record season I will change my mind.
Overall I think the data in many categories point to some moderate warming, but I do not see any acceleration, and a lot of data shows no real increases at all. I believe many predictions are starting to be proven false, but it is too early to be confident yet. The low arctic sea ice remains one of the strongest evidences of a warming planet, and I am very interested to see if it reaches a new low this fall or not. I am also interested to see how long the drought lingers and if it gets worse.
I have a bias that is skeptical of global warming, but I recognize that some evidence does exist, and I am not confident either way. I try to be as impartial as possible in my analysis, but please let me know if I have misconstrued or misinterpreted something. In three months, I’ll do it all again.