2014, according to Japanese, NOAA, and NASA measurements, was approximately 0.2 degrees Fahrenheit warmer than any previous measured year, or about 2 degrees Fahrenheit warmer globally than the early 1900s. 6 of its 12 months set monthly heat records. Scientists are now confident about asserting that this is the warmest it has been in the past 50,000 years, and we are rapidly closing in on clearly being warmer than at any time in the last 5 million years.
As James Hansen has recently noted, the global temperature more or less parallels the increase or decrease in carbon in the atmosphere, with each doubling being associated with a 4 degrees Centigrade (about 7 degrees Fahrenheit) increase in global temperature. About 2/3-3/4 of this is from the effects of atmospheric carbon dioxide itself, and 1/3-1/4 due to linked increases in black carbon, methane (CH4), and the like. Thus, since we are about halfway between our 1800s starting point of 250-280ppm of atmospheric carbon and a doubling of that amount, we have essentially “baked in” an increase of about 2.3 degrees Centigrade or 4 degrees Fahrenheit – the level at which, according to some scientists, catastrophic effects start to occur. What consequences? Movement of drought-ridden subtropical zones north to encompass much of the US except the Northeast, much of Southern Europe through France and Germany, and places such as the Fertile Crescent, India and Southern China. Loss of all Arctic sea ice as well as some Greenland and Antarctic ice, for a potential total (including expansion of the ocean through warming) of perhaps 25-80 feet. Loss of at least 1/3 of presently arable land, to be replaced by Canadian, Argentinian, and Siberian land that is presently mostly tundra and permafrost, and which would likely become fly-ridden, easy-to-burn-via-methane, peat swamps. Speed of winds in storms on average might increase by 10 mph.
But the “worst consequences” occurring if we go ahead and use more than 17% of present coal reserves, more than 50% of available oil and natural gas, and more than a small fraction of tar sands and oil shale, are far more dire. A rise in sea level of 216-240 feet. Possibly, iron blooms periodically releasing unbreathable sulfuric acid, making living near the new sea coasts impossible. Loss of perhaps 90% of arable land, making it impossible to feed more than about 1 billion people on minimal rations. Acidification of oceans that means destruction of all ocean-based food sources. Heat that makes working outside during 6 months of the year a death sentence. Storms in which the wind speed increases by more like 40 mph, so that the average high wind is a 110-mph hurricane, and somewhere in the world just about every year there is a 200-mph hurricane bearing down on humanity.
So how are we doing in avoiding “worst consequences”? Well, there are lots of encouraging superficial signs, including international agreements, preliminary data suggesting that Europe and the USA are decreasing their carbon emissions in constant terms, and so on. The problem is that such data is partial – for example, the emissions data just tracks carbon emissions via industry-based estimates and for those sources we don’t know about. There’s really only one holistic indicator, approximate as it is: the amount of CO2 in the atmosphere measured at the Mauna Loa volcano in Hawaii. You can find the data by googling “CO2 Mauna Loa”.
This set of measurements was started by Charles Keeling in 1950, and he picked a spot high on Mauna Loa because it was out of the way of the kind of things that would contaminate measurements. Interestingly, it has been joined in the last few years by a new measure based on widely dispersed global sites, which until recently had tracked 10 ppm less than Mauna Loa. In the latest data, it is now virtually identical at at 400 ppm, suggesting that the original global sites were contaminated more than expected and biased in a downward direction. At any rate, the new global measurements, like the old, tend to “smooth out” the more jagged spikes and dips in CO2 ppm yearly growth as measured by Mauna Loa. So Mauna Loa is more volatile, but the two agree in both the amount and trend over periods of perhaps 5 years or so.
What is Mauna Loa saying about the last 3 years? These years, in which the world economy is mostly flat or down – which should lead to decreased carbon emissions – and various policies have been implemented to reduced emissions, notably in Europe, are also the first years in which the CO2 growth has been above 2 for each year. In fact, according to the global “smoothed” data, it has been above 2.4 ppm each year. Not only are we not making progress; things are getting worse.
How can this be? Speculation is a bit early, but what it suggests is that US efforts are counteracted by attempts to “grow domestic oil production”, and that European efforts are more than counteracted by Chinese increased coal use (despite its rhetoric). I conclude that we must run faster to fall behind slower, and at an amazing speed just to stay in the same place. Happy New Year.