By 2050, the world population is projected to be about 9 billion people – about 1.6 billion more than the Earth supports today. What will that world be like? How much of the Earth’s surface will be used for agriculture, for housing, for managed and wild forests? How much of the land, and sea, will be used to power that world? What will the climate be like, as more humans demand more from the planet’s resources?
Those are the types of questions that environmental scientist Deborah Lawrence is asking, and trying to answer, with a diverse group of University of Virginia faculty members and students. The group is made up of environmental scientists, ethicists, psychologists, anthropologists, engineers, economists and lawyers, all working together to understand the big issues of the future that can be affected by the actions of people today. Their project is funded through a “Global Programs of Distinction” grant from the UVA Provost’s Office and funding from the John D. and Catherine T. MacArthur Foundation.
Lawrence specializes in exploring the effects of land use over lengthy periods of time for a big-picture view of how human activities affect ecosystems and climate and, likewise, how human populations may be affected by changes to the environment. She has earned distinction as a Guggenheim Fellow, a Fulbright Scholar and just this month, as a new fellow at the Center for Advanced Studies in Behavioral Sciences at Stanford University. She has served as a Jefferson Science Fellow at the U.S. Department of State.
UVA Today science writer Fariss Samarrai recently asked Lawrence about her project.
Q. Through the Global Programs of Distinction grant, you are trying to understand how the Earth will be in about three decades. Why did you pick the year 2050 to investigate?
A. Our “Food, Fuel and Forests” program is interested in alternative land-climate futures. As society addresses our changing climate, we have two major choices to make: Where will we get our energy? And what will we do with the land? The two are connected, and both affect climate. The land can provide energy, through biofuels, or it can offset the impacts of fossil fuel use, because forests take up and store vast amounts of carbon dioxide. Time lags in our climate system mean the impact of our choices today will only be felt after several decades. By 2050, the consequences of those choices will be clear.
When we model alternative land-climate futures, we need to look far enough out to see the impact of the policy choices we are contemplating today. We simply cannot see the effect in a few years – not in the real world, and not in the realm of models.
Q. You are working with leaders from across the disciplines. How can this range of views, many of them coming from non-scientific backgrounds, bring greater understanding to Earth science?
A. Humans have become one of the largest forces driving the dynamics of the Earth system. While we are subject to all the laws of physics, our behavior is also governed by so much more. We scientists cannot truly understand how the Earth functions without understanding why people do what they do. We cannot figure out how to limit climate change without seriously examining what motivates us to care and to act. The models tell us very little about why humans act the way they do, and that deeper understanding is necessary to find solutions. Our partners in law, psychology, ethics and anthropology add critical insights.
Q. What are you finding so far? Do you think climate models can give us a good sense of how the Earth and climate will respond to rapid population growth?
A. Our Earth system models do a great job of capturing the physical mechanisms that translate human actions into reactions. The growth of the population and improvement in standards of living worldwide put added pressure on the land and create demand for energy. The climate models alone do not tell us what kind of energy we’ll use, or where we will clear new land. We use socio-economic models for that.
We are finding that tropical forests play a very important role in regulating climate, both in the region where they occur and globally. Tropical forests are ground zero for increasing production of food and biofuels. Our future population needs both, but our work shows that people also need the climate stabilization provided by the forests that food and biofuels would replace.
Q. How far out can you reasonably predict? What might the world be like by the end of the century?
A. Unlike predicting the weather, predicting climate gets easier the further out you go in time. The real challenge in predicting our future is not in translating our choices into climate, ecosystem and human impacts, it is in figuring out which choices we will actually make. If nothing changes, business as usual leads us to a much warmer world at the end of the century – almost as much change from now as occurred from the end of the last ice age to the present. Think of what a difference that warming made. We are very confident about the long term warming response to increasing CO2.
However, things do change. Society changes – not only the tools and technologies we enjoy, but the importance we place on our relationship to the environment, community and culture. Who we become over the next couple of decades will determine our choices and our future climate.
Q. What scares you about the future, and what gives you hope?
A. What scares me is that the response to rising temperature may not proceed in an orderly, linear fashion. Processes regulating tropical forests or crop productivity or storm intensity or loss of Greenland’s ice may hit a tipping point and move very quickly. Feedbacks, particularly in biological systems, could result in even more warming. The example about which I worry most is permafrost melting in the far north, unlocking vast amounts of carbon dioxide that have been stored away for millennia.
But I am hopeful. More and more, I am convinced we are not on the path of business as usual. In Paris, 196 countries promised serious action on climate, including the most important ones – China and the U.S. I also see increasing commitment by people, young and old, in the U.S. and beyond, by local and state-level governments, and by business. We can make a difference, and I think we will.