This is an adaptation of a talk delivered February 26 at the National Press Club. Comments relating to policy are Dr. Hansen’s personal opinion and do not represent a NASA position.
There’s a huge gap between what is understood about global warming by the relevant scientific community and what is known about global warming by those who need to know: the public and policy-makers. We’ve had, in the past thirty years, one degree Fahrenheit of global warming. But there’s another one degree Fahrenheit in the pipeline due to gases that are already in the atmosphere. And there’s another one degree Fahrenheit in the pipeline because of the energy infrastructure now in place–for example, power plants and vehicles that we’re not going to take off the road even if we decide that we’re going to address this problem.
The Energy Department says that we’re going to continue to put more and more CO2 in the atmosphere each year–not just additional CO2 but more than we put in the year before. If we do follow that path, even for another ten years, it guarantees that we will have dramatic climate changes that produce what I would call a different planet–one without sea ice in the Arctic; with worldwide, repeated coastal tragedies associated with storms and a continuously rising sea level; and with regional disruptions due to freshwater shortages and shifting climatic zones.
I’ve arrived at five recommendations for what should be done to address the problem. If Congress were to follow these recommendations, we could solve the problem. Interestingly, this is not a gloom-and-doom story. In fact, the things we need to do have many other benefits in terms of our economy, our national security, our energy independence and preserving the environment–preserving creation.
First, there should be a moratorium on building any more coal-fired power plants until we have the technology to capture and sequester the CO2. That technology is probably five or ten years away. It will become clear over the next ten years that coal-fired power plants that do not capture and sequester CO2 are going to have to be bulldozed. That’s the only way we can keep CO2 from getting well into the dangerous level, because our consumption of oil and gas alone will take us close to the dangerous level. And oil and gas are such convenient fuels (and located in countries where we can’t tell people not to mine them) that they surely will be used. So why build old-technology power plants if you’re not going to be able to operate them over their lifetime, which is fifty or seventy-five years? It doesn’t make sense. Besides, there’s so much potential in efficiency, we don’t need new power plants if we take advantage of that.