The one thing you need to know about President Obama's plan to address climate change is that the most it will accomplish is slowing very slightly the pace at which the world is currently hurtling toward catastrophic climate change. Having said this, his plan is nonetheless a brave and even historic move in a country whose political campaigns and public discourse have been utterly poisoned by the science-free propaganda of the fossil fuel industry.
I would be more enthusiastic about the president's baby steps if the devastating droughts and floods and swiftly melting ice in the polar regions and mountain glaciers weren't telling us that drastic action is necessary right now. Nature doesn't really care about the timetables of politicians or about what is politically feasible. Nature doesn't negotiate, and it doesn't compromise. The laws of physics and chemistry cannot be repealed or altered by the Obama administration, the United States Congress or any other body. And, these physical laws are deaf to complaints about the negative economic consequences of addressing climate change--consequences that will be far worse if we do nothing about climate change.
But let me return to the goal announced by the president and put his plan into perspective. Using existing executive powers--mostly through the U.S. Environmental Protection Agency which the Supreme Court affirmed in 2007 has the power to regulate greenhouse gases--the Obama Administration will endeavor to reduce the RATE of greenhouse gas emissions in the United States to 17 percent below the RATE in 2005 and do this by 2020. It's a relatively easy target because half the reduction has already taken place. In recent years electric utilities have been changing from coal to cheaper and cleaner-burning natural gas to fuel their plants, and drivers, stung by unemployment and high gasoline prices, have reduced their driving.
I've put the word "RATE" in all capitals above because this one word gets to the heart of the matter. The plan does NOT propose to reduce the absolute concentration of carbon dioxide in the atmosphere, the major greenhouse gas which recently topped 400 parts per million (ppm). Instead, that concentration would continue to rise--even though it is increasingly evident that we must now reduce that concentration (some say to below 350 ppm) in order to avoid the worst.
The proposed decline in the rate of U.S. emissions would only reduce the overall rate of world emissions by just 1.6 percent based on 2011 emissions figures (using carbon dioxide as a proxy for all greenhouse gas emissions). Of course, other countries will have to do their part if we are to succeed as a species in addressing climate change. But it is worth noting that while the United States is home to just 4.5 percent of the world's population, it currently produces 16.8 percent of the world's carbon dioxide emissions. (The 2011 emissions were 5.49 billion tons for the United States and 32.58 billion tons for the world.)
I often refer to climate change as a rate problem. By this I mean that the rate at which we are dumping greenhouse gases into the atmosphere exceeds the rate at which the planet can remove them. Because the rate of emissions has consistently exceeded the rate of absorption by the Earth since the beginning of the industrial revolution, the absolute concentration of greenhouse gases has steadily risen. (The oceans, the forests, and the weathering of rocks are responsible for almost all of the carbon absorbed from the atmosphere. Were it not for these, the atmospheric concentration of carbon would be about twice what it is today, and we would long ago have have passed into a planetary emergency.)
Now, logic tells us that the only way we are ever going to get the absolute concentration down is to make it so that the rate of emissions falls below the rate of absorption by the Earth. And, that would require a drastic cut in the rate of emissions by more than 50 percent. But if we are to avert catastrophe, we must go much further so that the concentration can be brought down before a permanent new climate regime gets established. In other words, human survival depends on avoiding the tipping point in climate change that would render any human action ineffectual.
(Keep in mind that time is of the essence because climate change lags by 25 to 50 years the emissions that cause that change. We are only now experiencing climate change caused by greenhouse gases emissions between the early 1960s and the late 1980s. Even if all emissions ceased today, we would be in for another generation or two of warming.)
The oft-used phrase "tipping point" in this case refers to self-reinforcing loops in Earth processes that once started cannot be stopped by human action. Perhaps the most troubling example is the release of carbon dioxide and methane in the Arctic from the permafrost. The permafrost is now melting at an alarming rate and releasing greenhouse gases from the decay of dead plants formerly immune to such decay because they were frozen. The amount of carbon contained in the permafrost is nothing short of stupendous, twice as much as is currently in the atmosphere. The methane portion of any release is at least 20 times more potent than carbon dioxide in warming the planet .
Once this vicious cycle gets going, it will be unstoppable as warming temperatures melt more permafrost which then releases more greenhouse gases which then increase the temperature which means further melting and so on until the globe reaches a new stable climate that is much, much hotter than our current one.
But this isn't the only self-reinforcing loop that imperils us. Another is the declining albedo or reflectivity of the Earth at the poles as snow and ice disappear more frequently from larger and larger land and water surfaces as a result of rising temperatures. Snow and ice have high reflectivity and return much of the Sun's light to outer space. But land and water absorb much more of the light and turn it into heat which then melts adjacent snow and ice which creates ever larger areas of heat-absorbing open ocean and exposed land surface.
It's no wonder then that many scientists are calling for an 80 to 90 percent reduction in the rate of emissions by 2050. It's not simply about slowing warming. It's about stopping and possibly reversing it so as to stay away from climate destabilizing tipping points.
I haven't even touched on a subject which seems almost taboo, even among policymakers who are eager to tackle greenhouse gas emissions from utilities, factories, homes and vehicles. Meat production is so energy intensive that it is estimated to contribute about 18 percent of all greenhouse gas emissions each year. Telling people to reduce their meat intake, however, could prove to be even more unpopular than telling them to drive less or to lower their thermostats in winter.
And, deforestation--primarily in the world's rainforests--contributes nearly as much as meat production each year to climate change, about 15 percent of world greenhouse gas emissions. Felled forests cease to absorb carbon dioxide and instead emit it as the waste wood and other dead biomass left behind decays.
The application of nitrogen fertilizers, essential to the so-called green revolution around the world, releases copious amounts of nitrous oxide, a potent greenhouse gas. Today's large human population would not have been possible without nitrogen fertilizers which played a leading role in raising crop yields. It is thus going to be difficult to reduce nitrogen fertilizer use.
Then, there are several industrial gases. These compounds are extremely long-lived in the atmosphere--one lasting up to 50,000 years--and they are very potent, three of them exceeding the warming potential of carbon dioxide by more than 10,000 times. Some have been banned. Others are still in use. While their small concentrations in the atmosphere means that their contribution to climate change remains small, they are nevertheless worth addressing.
So, any credible climate change response must also address these other sources of emissions as well. The president's plan does touch on deforestation, but only briefly. The word "meat," however, does not appear anywhere in the report. In fairness, the president of the United States does not control world forests, nor can he change American farm policy--let alone American eating habits--single-handedly. While hydrofluorocarbons--used to replace now banned ozone-layer killing chlorofluorocarbons as refrigerants--are mentioned, nitrous oxide, a major greenhouse gas, is omitted. Yes, agricultural practices are mentioned, but the use of nitrogen fertilizers is THE major agricultural practice alongside meat production that generates climate warming gases.
The public needs to understand that the sources of greenhouse gas emissions are far more varied than most realize. And, the public also needs to understand that declines in the rate of emissions--unless very steep--are likely to be too little, too late. That's because it is the absolute concentration of greenhouse gases in the atmosphere that largely determines the climate. And, this concentration needs to start falling soon if we are to make certain that we avoid a climate catastrophe.