The U.S. Climate Change Science Program has released a major report detailing how climate change may affect the United States in the coming years. The study finds that:
- There is no question that climate change is occurring and that it is primarily human induced;
- Climate changes are happening in the United States and are projected to grow;
- Climate change will stress water and agricultural resources; and
- Tipping points in climate change have already been reached and have led to large changes.
Nature.org talked with Jonathan Hoekstra, former director of The Nature Conservancy’s climate change team, about the report, what the Conservancy is doing to address climate change and what type of planet we may be leaving future generations if we don’t act soon.
"The report makes clear that what we already know – the changes we have observed, the impacts we have experienced and those that are very likely to come – call for immediate action. Delay will only make the problems worse and the solutions more difficult."
former Director of The Nature Conservancy's climate change team.
How important is it for the United States government to be publishing a study with a top finding that states: “Global warming is unequivocal and primarily human-induced”? Does it increase this country’s international credibility on tackling climate change?
The report really is for the American public. It it lays out what climate change means for Americans in a way no other report has before. One of the reasons we haven’t been engaged in international climate change negotiations is because climate change has not been a problem in the hearts and minds of Americans. This report helps to make climate change a personal issue to people in this country.
It should motivate the United States to become a leader in the global dialogue about how we will act to address this challenge. The report identifies many important issues for which we need to increase our scientific understanding. Yet it also makes clear that what we already know – the changes we have observed, the impacts we have experienced and those that are very likely to come – call for immediate action. Delay will only make the problems worse and the solutions more difficult.
The study discusses how climate change will affect different regions of the country, which parts of the country will be effected the most?
To me this is less about where the deepest impact will be and more about an appreciation that the impacts will be nationwide and widespread. It’s going to call for responses everywhere. The Conservancy has been working where those effects were first apparent – where warming seas were bleaching corals and rising seas were eroding shorelines. We started taking action in those places years ago.
In forest systems, the effects of climate change are now emerging in the form of massive beetle and pest outbreaks and changes in forest structure. We’re working there as well in our management of forests to ensure that those ecosystems and the resources they provide are robust into the future.
We’re starting to see ramifications in our water supply – particularly in the West – as well as changes in precipitation that are altering flood dynamics.
These sorts of impacts have motivated the Conservancy to work with partners like the U.S. Army Corps of Engineers to rethink and retool the way we manage dams so we can make sure the water is there for people and nature into the future.
The study also discusses some tipping points for climate change which, when reached, could alter natural landscapes forever. Have we reached any tipping points yet which have changed natural areas for good?
If you define a tipping point as a change that’s irreversible, I think we have crossed some tipping points. Sea-level rise is inexorably redrawing our coastlines as shores erode and low-lying land is inundated. We’re going to have different coastlines because of sea-level rise.
The beetle outbreaks could also be one. It used to be that you’d get an outbreak, but the next winter it would get put down. Now the winters aren’t cold enough to put those outbreaks down, so they’re lasting longer and we’re seeing more tree mortality. As those trees die, the warmer climate may no longer be conducive to forest regrowth.
The study calls for more research on the ecological and social responses to climate change as well as the effectiveness of adaptation, noting that our understanding of these issues is “limited.” As a climate change scientist, do you think this is a fair assessment?
The pace and severity of climate change that we are experiencing is unprecedented, so it would be naïve to think that we know everything we need to know. The reason to call for more research is to reduce uncertainty about how climate change will affect us, and to become more confident in our ability to effectively adapt. Uncertainty creates risk. By investing in continued research, we can reduce the risk that we choose actions that don’t work, or that we are surprised by some impact that we did not anticipate.
Given the bleak picture of this report, what kind of world do you think we will be leaving for future generations?
Well, I’ll tell you what I hope. I look back to when I was a kid. At that time, you weren’t supposed to swim in the local lake or river because the pollution was so bad. It was like that across much of the country, and it spurred a period of environmental awakening around the country – around issues of air quality, water quality and endangered species.
Society stepped up and fixed those seemingly insurmountable problems. A generation later, we practically take for granted that most lakes and rivers are clean and swimmable and fishable. The world is not a pristine garden of Eden, but we have cleaned up the environment and improved our quality of life.
Today might be another period when we rise up to confront a global environmental challenge. A generation from now, I hope we might have a world where we have stabilized the climate and we take for granted that a healthy natural environment sustains our lifestyles and livelihoods.
About the Interviewee
Jonathan Hoekstra directed the Conservancy’s Climate Change Program, providing strategic and scientific leadership for our policy, science, and field-based efforts to reduce greenhouse gas emissions by protecting and restoring forests, and to help people and nature adapt to unavoidable climate change impacts.