The State of the World’s Ecosystems: A Conversation with Walter Reid


In 2005 the United Nations released the Millennium Ecosystem Assessment, an international synthesis by over 1,000 of the world’s leading scientists that analyzed the state of the Earth’s ecosystems and the services they supply to support humanity, along with scenarios and recommendations for the future. Six years later, Solutions checks on the effect of the report with biologist Walter Reid, who directed the assessment. Reid is currently the director of the Conservation and Science Program at the David and Lucile Packard Foundation.

The Millennium Ecosystem Assessment was an ambitious effort to check the health of the world’s ecosystems and the services they provide. What were the key findings of your report?

It was stunning to many scientists to see the scale of the impact that humans had had on the planet and ecosystems in the last 50 years. There was an exponential increase in drivers of change and resource consumption over that time. Take fishery harvests, for example. In 1950 fish catch for most species in most regions was still growing but, by 2000, harvests had peaked and were declining across the oceans.

The rate of forest loss and water consumption also grew dramatically. Water withdrawals doubled between 1960 and 2000 and more land was converted to cropland in the 30 years after 1950 than in the 150 years between 1700 and 1850. More than half of all synthetic nitrogen fertilizer ever used on the planet up to that time was used between 1985 and 2000. So, one message was the extraordinary pressure we’ve been placing on ecosystem services in such a short period of time.

The second message was that these changes to global ecosystems had a profoundly negative impact on ecosystem services. The assessment concluded that 60 percent of ecosystem services were declining. Not all. Food production from agricultural systems, for example, was enhanced. But many provisioning services, like fisheries, and most regulating services, like water purification, were in decline. There are often trade-offs involved in the choices we make about what ecosystem services we desire, but a clear takeaway from the assessment was that we don’t have the balance right—we are seriously degrading ecosystem services with profound consequences for human well-being.

The third message was more positive: that under certain scenarios we can reverse the degradation of ecosystems, although this will require significant changes in policies and institutions. We looked at four different scenarios out to 2050 and, in three of the four, various changes in technology, management, and policy could mitigate many of the pressures on ecosystems. But I don’t want to make the picture sound too rosy. While the scenarios revealed real opportunities for progress, they required changes that are not currently taking place, and the ongoing growth of GDP and human population is placing ever-increasing pressure on ecosystems.

So, the MEA found that, with appropriate actions, it is possible to reverse the degradation of many ecosystem services over the next 50 years, but that the changes required were substantial and not currently under way. Has anything changed?

There have been positive changes, but primarily in individual nations or regions. At the global level, where we ultimately need progress to address global drivers like climate change, there really hasn’t been much progress.

So, it’s been disappointing?

It has. We haven’t made much progress. There have been individual successes: carbon farming in Australia, Brazil’s progress in reducing deforestation over the last decade, logging bans in Thailand and China, and the rebuilding of fisheries in a number of countries. But, in the aggregate, I don’t believe that the trend of degradation has been reversed for any of the individual ecosystem services that were being degraded in 2000.

The idea that nature is an asset that is at least as important as our other economic assets in supporting human well-being is very different from the typical jobs-versus-the-environment framing of the issue. Has this new framing taken hold and is it forming the basis for real solutions?

The results are mixed. That framing works well for some audiences and not for others. In developing countries, there was considerable receptivity to this framing—presumably because the linkages between ecosystems and human well-being are so readily apparent. Within the industrialized countries, there is often more resistance to the idea of, in some sense, putting a price tag on nature. In my view, though, there is less conflict between ethical and economic arguments than many critics assume. If we don’t make economic arguments and note benefits to human well-being when they clearly are justified, then we will fall short of goals for both conservation and human well-being.

Where the framing is taking hold, it is forming the basis for solutions. Payments for Ecosystem Services programs in South America are a good example, as is the emergence of carbon markets associated with forest conservation and agricultural practices.

What are some of the lessons learned from the assessment?

The biggest lesson was, not surprisingly, that ecosystem services are most relevant to decision makers at a landscape scale. Even though the global risks and threats are most compelling at the global scale and in the aggregate, it is not at the global scale that we can do much about the problem. In the Millennium Assessment, we sought to address this by carrying out a multiscale assessment with some global elements and some subglobal assessments, but this still didn’t provide decision makers at the scale of a state or county with the sort of actionable information that they needed. What’s really needed in the long run is for much more work to be done to provide ecosystem service information at these more local scales and then to periodically roll it up so we understand the global consequences and trends.

What should we be thinking about now, going forward?

The most useful thing right now is to build up the examples where ecosystem service analyses have directly informed decision makers, who then become advocates for this type of analysis. There are many studies done by the scientific community. We still don’t have enough examples where decision makers—county, state, or federal government officials or corporate CEOs, for example—have used an ecosystem service analysis to come to a decision they wouldn’t have come to otherwise. There are certainly more examples of this today than ten years ago, but it is worrisome that there are still relatively few. We will know that the ecosystem services approach has succeeded when we are more likely to hear decision makers saying that this is important than we are to hear the scientists saying that it should be important.

Given the current state of the world and of ecosystem services, what changes are most critical in order to move toward a sustainable and desirable future for humanity?

At a macro level, one of the biggest constraints for many developing countries is weak governance and rule of law. Even if you had the right policies in place—and few countries do—there is often little hope that they could be enforced. And, in many countries, there remain fundamental problems associated with the recognition of rights to resources and land tenure that make it almost impossible to imagine successful management of ecosystem services. In developed countries, where there is better governance and rule of law, we still are not making wise trade-offs in our management of ecosystem services. Services with a market value are always given priority over nonmarket services at considerable cost to the public and to human well-being as well as to the environment. Whether through markets or regulations, steps need to be taken to elevate the priority given to these threatened ecosystem services. In addition, we clearly need to address climate change. This is already one of the greatest threats to ecosystems and their services and that threat is growing rapidly.