The uncertainties about climate change are many and great. How much CO2 may join the atmosphere if nothing is done about it? How much global warming will it cause, and how will local climates, ecosystems, and vulnerable species be affected? What impact will such changes have on productivity, comfort, and health? And, of course, what are the likely costs of shifting to renewable energy sources and energy conservation?
As more becomes known about climate change – for example, the role of clouds and oceans – more uncertainties emerge. Nevertheless, the greenhouse “theory,” as it is sometimes disparagingly called, has been established beyond responsible doubt. There is uncertainty about the quantitative parameters, and there can be doubt about whether the warming of recent decades is entirely due to the “greenhouse effect.” But the basics of global warming are not in scientific dispute.
If we know that the earth is warming, but are uncertain about how fast and with what effects on climates worldwide, what are the most urgent steps that we should take to address it? One, of course, is to keep studying climate phenomena and their ecological impact. Another is to promote research and development aimed at remediation. We urgently need to understand what alternatives to fossil fuels there will be, how much energy can be conserved, how to extract CO2 from the atmosphere, and, if necessary, how to increase the earth’s albedo, its reflectance of incoming sunlight.
One way to ensure the necessary R&D is to rely on the market to finance and direct the work by using taxes, subsidies, rationing, and – most important – by convincing firms and consumers that fossil fuels will become progressively more costly. But private interests will not undertake some essential R&D under any circumstances; the “market” will not induce the necessary outlays, because investors cannot capture all the benefits of moderating global warming for the human race.