James Hansen on Climate Tipping Points and Political Leadership

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In my opinion, it is still feasible to solve the global warming problem before we pass tipping points that would guarantee disastrous irreversible climate change. But urgent strong actions are needed.

It is clear that the required course is technically feasible, and it would have great benefits to the public in developing and developed countries. The geophysical facts practically dictate the way.

Unfortunately, knowledge and understanding of the situation are not widespread. In addition, there is a minority of people, termed “fossil interests,” who benefit from business-as-usual. These fossil interests have enormous influence on governments worldwide, far outside their fair role in democracies.

Climate Situation

Our global climate is nearing tipping points. Changes are beginning to appear, and there is a potential for rapid changes with effects that would be irreversible – if we do not promptly slow fossil fuel emissions during the next few decades.

Tipping points are fed by amplifying feedbacks. As Arctic sea ice melts, the darker ocean absorbs more sunlight and speeds melting. As tundra melts, methane a strong greenhouse gas, is released, causing more warming. As species are pressured and exterminated by shifting climate zones, ecosystems can collapse, destroying more species.

We already have caused atmospheric carbon dioxide to increase from 280 to 387 ppm (parts per million). What science has revealed in the past few years is that the safe level of carbon dioxide in the long run is no more than 350 ppm. The optimum CO2 level to support civilization may be less than 350 ppm, but more precise knowledge is not needed immediately for the purpose of establishing present policies.

The conclusion that CO2 must be reduced to a level below 350 ppm was startling at first, but obvious in retrospect.

Earth’s history shows that an atmospheric CO2 amount of say 450 ppm eventually would yield dramatic changes, including sea level tens of meters higher than today.

For reference, 450 ppm yields global warming about 2°C (3.6°F) above the preindustrial level. Such a level of atmospheric CO2 and global warming imply that we would hand our children and grandchildren a condition that would run out of their control, a situation that should be unacceptable to humanity.

Fossil Fuels

Human-made sources of atmospheric carbon dioxide are summarized in the graph at right. The dark portions of the bars are the portions of the fuels that have been burned with the carbon put into the atmosphere as carbon dioxide. The size of fossil fuel reserves (the fossil fuel not yet extracted from the ground) has significant uncertainty.

An important point is that the size of recoverable reserves depends upon whether drilling is allowed in off-shore regions, public lands, polar regions, and the deepest ocean. Similarly, the amount of coal reserves that is practically minable is uncertain and depends upon the degree to which ever more destructive mining practices are allowed. Unconventional fossil fuels (tar sands, oil shale, methane hydrates), not shown the first graph, are similar to coal in their high carbon content and have reserves that may be comparable in size to coal or even larger.

Despite uncertainties in reserve sizes, it is clear that if we burn all the fossil fuels, or even half of the remaining reserves, we will send the planet toward an ice-free state with sea level about 250 feet higher than today. It would take time for complete ice sheet disintegration to occur, but a chaotic situation would be created with changes occurring out of control of future generations.

Oil may already be about half depleted, i.e., the world may be close to peak oil production (implying that the IPCC estimate of reserves is closer to the truth than the EIA estimate). In either case, common sense suggests that the largest oil pools will be exploited and the carbon dioxide, which is emitted mainly from tailpipes, will end up in the atmosphere.

Gas, the least carbon intensive and cleanest burning fossil fuel, also surely will be exploited.

The obvious conclusion is that the only practical way to avoid climate catastrophe is to terminate emissions from the largest fossil fuel source: coal, the dirtiest of the fossil fuels. If coal emissions are phased out between 2010 and 2030, global fossil fuel emissions would begin to fall rapidly as shown in the chart below.

The rate of emissions (shown in billions of tons of carbon on the left and in percent of 2008 emissions on the right) depends upon how much oil and gas is used. The (red) curve showing larger emissions is based on the assumption that the larger reserve estimates of EIA are valid and all of the CO2 is emitted to the atmosphere. These emission scenarios have been converted to atmospheric CO2 amounts using a simplified version of the Bern carbon cycle model.

The next chart shows that atmospheric CO2 would peak at only ~400 ppm in ~2025, if the IPCC oil and gas reserves are accurate and if coal emissions are phased out uniformly over the period 2010-2030.

If, however, the EIA oil and gas reserves are accurate (and if coal emissions are phased out), atmospheric CO2 will peak early in the second half of this century and atmospheric CO2 will be about 30 ppm higher than with the IPCC reserve estimates.

The EIA reserve estimates may be realistic if we choose to go after every last drop of oil by drilling off-shore, on public lands, in the Arctic National Wildlife Reserve, and in the deepest oceans, for example. With these larger reserves exploited, future generations, including our grandchildren, likely will be forced to seek ways to extract that extra 30 ppm of CO2 from the atmosphere. In the referenced paper we discuss the costs of air capture and disposal of CO2, estimating a cost of about $200 per ton of carbon. Thus the cost of removing 30 ppm would be about $12 trillion dollars, a burden that would be passed to our descendants.

The primary implication, however, concerns coal. The reason that CO2 peaks at only 400-425 ppm in these scenarios is the assumption that coal emissions will be phased out linearly between 2010 and 2030. Such a scenario is technically possible, but only with policies that lead to availability of appropriate alternative technologies and incentives for using them.

We must move beyond fossil fuels at some point. Why not do it sooner, for the benefit of our children?

Political Leadership

Political meetings may produce lofty goals for reduced carbon dioxide emissions by some future date. But these are of practically no significance if the goals and the actions of the nations are inconsistent with geophysical constraints.

For example, I spoke with a German Minister. We found that we were in good agreement with the startling conclusion that we are already moving into dangerous levels of atmospheric CO2. Yet Germany plans to build more coal-fired power plants. His rationalization was that they could “tighten the carbon cap” on cap and trade.

I pointed out that, if coal emissions continued, that cap would somehow have to force Russia to leave its oil in the ground. I asked how he would convince Russia to do that.

He had no answer.

The overwhelming practical requirement, for the sake of future generations, humanity itself, and the other species on the planet, is phase-out of coal emissions over the next 20 years.

The correct fundamental approach is a rising price on carbon emissions, as needed to achieve these objectives. The Waxman-Markey bill fails the test in the same way as the German plans: it builds in approval of new coal-fired power plants. There is no need for these plants except to enrich utility and coal special interests – they are included only because the monstrous 1400-page absurdity was hatched in Washington after energetic insemination by special interests.

Officials in the Obama administration privately admit that the science demands much more rapid emission cuts than Waxman-Markey would yield, but they say that their hands are tied by a recalcitrant Congress.

Is that so? Has President Obama provided direction or guidelines for what he expects from Congress?

This is a problem that demands strong leadership. The only special interest that should be calling the tune is the public’s special interest. Mountaintop removal should be banned. We should move rapidly to terminate coal use except where all emissions are captured.

The truth is that the climate problem cannot be solved without taking on special interests, specifically the coal industry. That is possible. The coal industry is but a fraction of what it once was; alternative industries will be far more beneficial to the nation and provide better jobs.

President Franklin Roosevelt, for the general good, took on more powerful special interests.

Margaret Thatcher showed that the coal industry is not omnipotent. This does not mean that coal workers should be abandoned – on the contrary, it would be straightforward to have programs in the affected states that provide support and opportunities for all of today’s coal workers.

President Obama is our best hope, perhaps the only hope, of achieving real change in the near term. But we have to level with him.

Civil Resistance

Another truth that has become apparent: our climate/environment leaders are not people located in Washington. The leaders are members of the public who understand the situation and have the courage to act on it.

I met a couple of them recently:

Tim DeChristopher, the University of Utah student, who, realizing that it makes no sense to be going after the last drop of oil on pristine public lands, outbid the oil companies for drilling rights. He has been charged with two felonies (because he had no money to pay for the drilling rights) and is threatened with 10 years in prison (he is facing about $100,000. in legal costs — you can contribute to his defense at peacefuluprising.org).

You can see a rationale for Tim’s defense in the above charts. The efforts of fossil interests to go after every last drop of oil may leave his generation with a $12 trillion cleanup bill – that’s just for restoring the air (removing 30 ppm of CO2), without consideration of payment for damage due to rising seas – and what is the price of species exterminated?

Larry Gibson, the Mountain Man near Coal River Mountain who refuses to let Massey Energy blow up the mountain where he lives and his relatives are buried. These are the people with real courage – it made me nervous just to ride in Gibson’s pickup in hostile territory. Larry and I both have pleaded not guilty to charges of obstruction during the protest on June 23 and are requesting a trial.

On the subject of civil resistance (Mahatma Gandhi explained why civil resistance, as opposed to civil disobedience, is a better philosophy), a recent note from Damian Carrington of the Guardian and Observer reads:

Given your involvement in the Kingsnorth trial, I thought you would be interested to know the result of the trial of the 29 people that stopped a coal train going to Drax. They were found guilty of the main charge after the judge ruled out the necessity defence. We have covered the trial extensively (unlike our competitors) and you can if you wish read more here. Their closing statement is quite something. I would very much like to include your reaction to the verdict. Could you send me a line or two?

I responded that they are right to keep the focus on the necessity defense.

Civil resistance is not easy, but if governments continue to abdicate their responsibility to citizens, in favor of special interests, it seems essential. Strength comes from realization of rightness of course, and should be increased, not diminished, by temporary setbacks.

(Excerpted from Strategies to Address Global Warming)


See also:

James Hansen on How Science Works

G8 Failure Reflects Congress’ Failure to Write Effective Climate Policy

Hansen: Protests May Be Only Way to Force Climate Action