For media or event inquiries,
please contact us.

Q&A On Key Issues

An Interview with Dr. Cynthia Rosenzweig of NASA – Q&A with Anna Lappé
September 2008

“It’s above Tom’s Restaurant,” says Cynthia Rosenzweig, offering a historic landmark to help me find her office at NASA’s Goddard Institute for Space Studies. (Yes, that would be the “Tom’s” made famous by cameos on Seinfeld).

Compared with this pop-culture icon, the Institute’s offices are particularly unremarkable. You enter a nondescript building off Broadway in upper Manhattan, near Columbia University, and sign in at a tiny security desk to next to a glass-encased directory.

In a true sign of global-warming geekiness, I admit I got a bit of a rush when my eyes landed on “Hansen, James.” Head of the Institute and science advisor to Al Gore, Hansen has long been a critic of the Bush and Clinton administrations for dragging their heels in addressing the greenhouse effect.

Twenty years ago, it was Hansen, a physicist by training, who told the Senate Energy and Natural Resources Committee: “The greenhouse effect has been detected, and it is changing our climate now. We already reached the point where the greenhouse effect is important.”

Dr. Cynthia Rosenzweig has been leading the Institute’s Climate Impacts research group for 15 years. With a particular interest in how global warming will affect food production in the future and how agriculture contributes to climate change, Rosenzweig has been developing international collaborative studies to examine both adaptation and mitigation possibilities.

With her background in farming – she has run diversified produce and livestock operations in Tuscany, Italy and upstate New York – and with Ph.D. training as an agronomist, Rosenzweig has a personal connection to the staggering data she collects. Aware of the complexity of the science of climate change, Rosenzweig has been influential in establishing global, collaborative research to work on interdisciplinary, national, and international studies of climate change impacts and adaptation.

Somehow, despite her grueling research schedule, she still finds time to teach and give talks. In just the past few months, I’ve heard her speak several times: once to a group of farmers in upstate New York, another time we shared the dais, speaking to policy officials gathered to offer suggestions for a United Nations response to the global food crisis. Each time, I was impressed by her command of the science and her ability to translate potentially impenetrable scientific data to those without intimate knowledge of the science of climate change. I began our interview with the question foremost on my mind.

I couldn’t help but notice that every time I’ve heard you speak about global warming–what for many would seem to be a depressing topic–you are so positive. How do you stay upbeat despite the grim projections?
I refuse to be pessimistic about climate change. It is simultaneously the significant environmental challenge of our time and future generations, and it is the issue that is leading us into sustainability. As you know, people have been talking about sustainability for quite a while. There would be lip service, but people could never think about sustainability in long enough terms.

Climate change actually forces sustainability on us. It forces us to consider the challenges and choices that we must make.

Right here in this building was where some of the first climate change models projected what increasing greenhouse gases could do to our climate. That was in the late ‘70s and early ‘80s – only 25 years ago. Look how far we’ve come! We’re renegotiating our second global treaty. Everybody on the planet knows this is happening and that we have to deal with this.

We’re no longer in the issue-identification stage. We’re rolling up our sleeves and trying things. Now, some things are working, some things are not, but the important thing is that we finally have something powerful enough to get the human species acting for sustainability, and that is why I refuse to be pessimistic.

I published an op-ed about climate change in a Seattle newspaper a few months ago. Within minutes of the post going online, it was hit with comments from climate change deniers. I didn’t think they were around anymore.
I’m a working scientist and there are always questions, always uncertainties. There are always things we don’t know. When we learn something new, that opens up ten things we don’t know. So, I welcome questions. I think it’s important to be honest that we don’t know everything about climate change, and that we have to keep learning. That being said, we certainly know enough about climate change to be sure that it is the significant environmental, planetary issue of our time, and that we have to deal with it even though we don’t understand it completely.

So that’s how I view this. It’s good to have hard questions. I think skeptics’ questions are helpful. They keep us honest.

In talking about global warming, you’ve noted that it’s important for people to understand that the trends point not only to warming but also to more extreme weather as well. Exactly how will agriculture be affected by these changes? I remember when you spoke with the New York farmers at Glynwood Center you told them that global warming could transform the climate of the state so that farming here would feel like farming in Georgia.
Exactly. But that’s only one part of the climate change story. Because when you have changes to the mean temperature, you’re going to have more extremes, too. More heat waves, in this case. And there may also be, beyond those changes related to the mean changes, changes in the intensity and frequency of extreme events as well.

Means and extremes affect agriculture in different ways. The means are what affect the cropping regions – what types of crops farmers can grow, such as barley in cooler climates and sorghum and citrus in warmer ones. If you have more heat waves and more droughts and floods – which the climate predictions indicate – these have very negative effects on crop and food production, whatever crop you are growing.

Who will be most affected, and vulnerable, to these changes?
What we found was that in the lower latitudes, where it’s warmer already, food production systems are the most vulnerable. This is due to both higher temperatures themselves, which tend to be detrimental to crop yields, as well as to water stress brought on by increases in “evaporative demand.” Biologically, agricultural pests also tend to proliferate in warmer climates. When we look where developing countries are located, we find that they are located primarily in the lower latitudes and are thus more likely to bear the brunt of climate change the soonest.

One of the main findings of the IPCC’s Working Group II is that developing countries are more vulnerable to climate change, and a big part of that is because their agricultural systems will be stressed by both the physical and biological aspects of climate change.

They’re more vulnerable for another reason, too: Agricultural systems in developing countries tend to have less well implemented adaptive capacities. In developed countries, there are land grant universities, research institutions, and extension programs; all this has been in place for decades. We have a whole system for breeding new varieties in response to changing climate. But in the developing world they’re already dealing with many other strains on their economies so that the vulnerability in the developing world encompasses both the physical and biophysical side and the socioeconomic side.

In the United States, I’ve noticed that estimates of our food system’s greenhouse gas emissions are quite low, even though we know that globally the food system contributes roughly one-third of all greenhouse gas emissions. In part, these estimates are so low because they’re just based on the food that is grown here, not the emissions of what’s eaten here.
I call that the “foodprint.”

Right, the foodprint: We need to look at the emissions of not just what’s produced, but what’s consumed here.
Exactly. Agriculture plays multiple roles regarding climate change. It is one of the major land-based sectors that is affected by climate and where adaptation is truly going to be central, and at the same time it is – after the energy-producing sectors for power, transportation, and industrial/commercial activities – the biggest contributor of greenhouse gases. It has multiple sources and emits multiple gases. Though, again, when we do the calculations, there’s this “leakage” problem. As you said, are we just measuring U.S. food, or are we measuring U.S. consumption?

Let’s talk about the carbon sequestration potential of agriculture.
Soil carbon sequestration can play an important part in the solution to climate change. I believe that every sector has to do their part. There has been some tendency to look for the silver bullets. Some colleagues say, ‘Okay, we’re going to do carbon capture from the power plants, then we’re going to react the CO2, and then we’re going to bury it, and that will take care of everything.’ This is sometimes presented as if no one else will have to do anything.

The sustainability challenge is so great that every sector has to step up and do their share. And agriculture is a leading sector, so that’s why I believe that we need to develop effective soil carbon sequestration programs within the sector. Now, that’s challenging, because there are issues of techniques, measurements, compliance, etc.

There are many people around the world working on developing soil carbon sequestration as a viable and documentable mechanism for reducing atmospheric climate forcing, but we need to come together to create a program by which the agriculture sector, particularly in developing countries, can be rewarded for storing carbon.

So, would it be analogous to being rewarded for protecting forests?
This is such a win-win solution, because we must continue to support robust agricultural systems in developing countries. In many circles, agriculture is considered a primary engine for development. Also, strengthening agriculture can help to stem people moving to cities. Local carbon sequestration program could support the development of healthy agricultural systems. It’s also ‘win-win-win’ because carbon sequestration on farmers’ fields helps to both mitigate greenhouse gas emissions and adapt to increasing droughts and floods. By holding more moisture, soil with high carbon content helps farmers face droughts and deal with floods. That’s why I like it so much! It helps out on both the source side (reducing emissions) and the response side (improving adaptive capacity).

How do you help people see farms as carbon sponges just like we see forests?
Trees store large amounts of carbon above ground, whereas crops can help to restore carbon to the soil through practices such as no-till and cover cropping. Of course, since the grain and at least some of the biomass is harvested in agriculture, some of the main carbon fixed is removed. Agricultural soil carbon sequestration tends to be lower on a per-unit basis, than forestry. But the widespread areas devoted to agriculture and the many farmers, particularly in developing countries, create a large potential contribution to climate change mitigation for agriculture. Where it makes sense, we can combine the two sectors in agro-forestry. So let’s reward farmers for storing carbon, because it helps to reduce soil erosion and to reduce the effects of climate extremes, as well as to reduce greenhouse gas forcing.

What lessons do you feel like we can learn from climate change policies that have not worked in the past?
We’re learning many lessons, for example, from the corn-for-ethanol program. One thing that I’ve been struck by is the rapidity with which the program has been picked up when there are actual dollars involved. I mean isn’t it amazing how quickly ethanol production went forward. The private sector is indeed ready to jump into action to help to mitigate emissions. But that means we have to be much more careful. We have to think through the sustainability of the programs before we put them in place. In this case, we have to examine the actual mitigation potential of any particular biofuel system and its effects on the environment overall.

The climate change issue is changing the paradigm between scientists and other parts of society. Previously, scientists would raise an issue, and then they would pass it off to society. I think the corn-for-ethanol issue shows that such ‘silos’ do not work for finding solutions to climate change. What we’ve learned is that there needs to be far more interaction and integration among different groups of society as we confront the climate change challenge.

September 2008