Research by the University of Washington predicts that Earth is likely to exceed a temperature increase of 2 degrees Celsius by the end of the century. Using statistical tools, the research finds only a 5 percent chance that Earth will warm 2 degrees or less by the end of this century and only a 1 percent chance of achieving the goal of 1.5 degrees or less set by the Paris climate accord.
“Our analysis shows that the goal of 2 degrees is very much a best-case scenario,” said lead author UW Prof. Adrian Raftery. “It is achievable, but only with major, sustained effort on all fronts over the next 80 years.”
The research published today in Nature Climate Change, gives a 90 percent chance that temperatures will increase this century by 2.0 to 4.9 C.
“Our analysis is compatible with previous estimates, but it finds that the most optimistic projections are unlikely to happen,” Raftery said. “We’re closer to the margin than we think.”
Their research focused on three main factors that underpin scenarios for future emissions: total world population, per capita gross domestic product and carbon intensity. The reseachers used statistical projections for each of the three factors using 50 years of data in countries globally.
The projections conclude a median value of 3.2 C temperature increase by 2100, and a 90 percent chance that warming this century will fall between 2.0 to 4.9 C.
The researchers had expected to find that higher populations would increase the projections for global warming. Rather, they found that population has a fairly small impact because most of the future population growth will be in Africa, an area with little carbon fuel use.
The most important factor for predicting future temperatures is carbon intensity, which is the amount of carbon dioxide created for each unit of economic activity. Carbon intensity has improved around the world in recent decades as increase investment in renewable energy and efficiency.
“Overall, the goals expressed in the Paris Agreement are ambitious but realistic,” Raftery said. “The bad news is they are unlikely to be enough to achieve the target of keeping warming at or below 1.5 degrees.”
The research finds that the carbon intensity can vary wildly over the coming decades depending on technological progress and the level of global effort in implementing those technologies.
An Atomically Precise Solution
The development of atomically precise manufacturing (APM) is one such technology that could offer multiple ways to mitigate the effects of climate change.
One solution offered by APM was outlined by Dr. Ralph Merkle last month in a publication [PDF] from the Institute for Molecular Manufacturing. Dr. Merkle calculates that with very cheap solar power that AMP could make possible (APM could make printing thin solar panels cheaper than cardboard is today) and using molecular CO2 filters it should be possible to extract atmospheric CO2 compress it on a planetary scale.
Dr. Merkle concludes that, “The excess atmospheric CO2 produced by human activity could be filtered and compressed into a volume smaller than a cube with 10 km edges for an energetic cost of only 1 solar hour (the total energy that reaches the earth from the sun in one hour) assuming perfect efficiency of all steps.
If we include some reasonable degree of inefficiency for the various steps, when carried out by atomically precise molecular machines manufactured by nanofactories, we still incur an energy cost of no more than a few solar hours. Spread out over a decade or two, this energy cost is much less than 0.01% of the solar energy reaching the earth.
Once our ability to manufacture atomically precise molecular machines has been developed, removing undesired CO2 (or any other greenhouse gas) from the atmosphere will present no special technical challenges and could be powered by collecting a very modest percentage of the sunlight reaching the earth.”
Another scenario that could be enabled by APM was envisioned by J. Storrs Hall around a decade ago, it would involve building around 10 million of tons of programmable diamond balloons that would be around a nanometer thick and capable of reflecting sunlight.
Using these balloons would allow us to essentially set a thermostat for the planet, reflecting a precise amount of sunlight needed to maintain a desired temperature.