Professor James Hansen and a team of climate scientists from around the world released on Tuesday a scientific paper, "Assessing Dangerous Climate Change," to call for serious action now to address climate change. The scientists argue that Humanity has already delayed action enough that drastic action is now required to avoid catastrophic consequences, and that the longer we wait the more expensive and difficult will be the task.
The main point made in the paper is that the accepted target of "limiting human-made global climate warming to 2 degrees Celsius above the preindustrial level" is woefully inadequate, and would subject young people, our future generations, and the planets ecosystem, to irreparable harm. That target was confirmed by the 2009 Copenhagen Accord of the 15th Conference of the Parties of the United Nations Framework Convention on Climate Change.
In a statement accompanying the release of the paper, Hansen said the paper was "written to provide the scientific basis for legal actions against federal and state governments, in the United States and other nations, for not doing their job of protecting the rights of young people." The statement went on to say the "legal actions being filed by Our Children's Trust ask the courts to require the government to provide a plan for how they will reduce fossil fuel emissions consistent with stabilizing climate."
The risk seen by the scientists are irreversible consequences "such as sea level rise large enough to inundate most coastal cities, and extermination of many of today's species." Continued global warming will also worsen the climate extremes that are already hitting around the world, including stronger summer heat waves, more intense droughts, and wildfires that burn hotter. Warming, according to the scientists, causes "the atmosphere to hold more water vapor" which itself will cause stronger thunderstorms, tornadoes, hurricanes, typhoons, as well as heavier rainfall and floods.
They claim that warming could be held to about 1 degree C over pre-industrial levels if fossil fuel emissions are limited to 500 gigatons of carbon, and if policies are put into place which sequesters 100 gigatons of carbon back into the soil. That would lead to atmospheric CO2 level of 350 parts per million by 2100, restoring the Earth's energy balance, and stabilizing the climate.
The 2 degrees C target is insufficient because Earth's history demonstrates that this amount of warming is likely to result in sea level rise of 20 feet, and would induce "slow amplifying feedbacks" that include a reduction of ice sheet area, vegetation changes, and an increase in atmospheric gases like nitrous oxide and methane.
Cumulative fossil fuel emissions through 2012 are 370 gigatons of carbon and Humanity's rate of fossil fuel use adds 10 gigatons per year, giving us 13 years within which to act. The scientists calculate that a reduction of 6% per year in emissions will limit total emissions to the 500 gigatons level. If the reductions had begun in 1995 the rate of reduction required would have been only 2.1%. On the other hand, if we wait until 2020 to begin emission reductions, the rate of reduction must be 15% a year to stay within the 500 gigatons threshold.
In other words, the longer we wait the more difficult it will be to avoid catastrophic climate change.
It is crucial, according to the scientists, that the "major international powers today realize that we are all in the same boat together and we will all sink together or sail together."
Implementing their policy recommendations will certainly require international cooperation on a scale that is currently politically inconceivable.
The recommendation is to make a wholesale switch from fossil fuels (Coal and Oil) to nuclear energy and renewable energy resources. And because China is rapidly increasing its Coal usage as it rapidly industrializes, the scientists call for sharing advanced nuclear power plant technology with China.
The nuclear plants to be built are not the 40-year old technology we are saddled with in the nuclear disaster at Fukushima Japan. Advanced 3rd and 4th generation nuclear power plant designs can automatically shut down in case of anomalies, do not require external power to cool down, and can even run on nuclear waste materials like depleted uranium and excess weapons material.
To illustrate the size of the problem, charts supplied in the paper show current global energy consumption to be almost entirely based on fossil fuels, with renewable energy resources supplying less than 2% of global energy. Even that much only came on-line in the last couple years thanks to concerted effort to build more solar and wind power installations.
The concept that the current generation has an obligation to deliver an undamaged environment to the next generation was recognized by the U.S. founding fathers, such as Thomas Jefferson who argued th the soils must be left in equally productive condition.