What will the earth be like in 2050? The United Nations Millennium Ecosystem Assessment - a four-year global research initiative involving 1,300 scientists from 95 countries - offers some predictions. The work explores the world's ecological future and the complex relationship between human well-being and the health of the planet.
First the bad news: The Millennium Ecosystem Assessment finds 60 percent of the world's ecosystems degraded or used unsustainably, and between 10 and 30 percent of the mammal, bird and amphibian species threatened with extinction.
By 2050, the report predicts, the demand for water will have increased dramatically across the globe - between 30 and 85 percent - especially in Africa and Asia. Water will also be more plentiful in nearly all regions because of climate change, but growing human demands for that water will put the ecosystems that provide it under increasing pressure.
Food security is likely to remain out of reach for many people despite increasing global food supplies, but child malnutrition, while not eradicated, will likely drop over the coming decades.
Lead author Stephen Carpenter, professor of zoology at the University of Wisconsin, says despite what looks like a steady global decline, the report offers some hope. "The good news is that we can make a very positive difference in ecosystem services by 2050," he says. "The caveat is those policies and practices are not widespread at the present time, and substantial changes in policies and practices would have to be made in order to implement the beneficial ones at the global scale."
Carpenter says the assessment presents scenarios for sustainable development based on changes in such factors as economic and population growth, climate change and trade. "These scenarios give us a powerful way of exploring different options and their logical consequences and making appropriate choices to improve ecosystem services," he says.
Such appropriate choices, Carpenter says, would include making wise use of environmental technology, investing in education and health and reducing poverty to reduce pressure on ecosystems.
Those ecosystems, Carpenter says, have dramatically improved human health over the last centuries. People are better nourished, live longer and are healthier than ever before. But these gains, he says, have come at a growing cost to the environment.
The report suggests attaching monetary value to those ecological services that support life - from food, clean water, clean air and healthy soil to crop pollination and buffers against natural disaster. Assessment director Walter Reid says ecosystems today are grossly undervalued. "As long as we continue to treat ecosystems as free and limitless, we will continue to use them in a way that does not make economic sense," he says. "We need to make sure that we start looking at the value of all ecosystem services, not just those bought and sold in the market, and take those into account in decision making, use markets where that is possible, use payments for ecosystem services where that is possible."
There have been some steps in this direction, says Prabhu Pingali with the U.N. Food and Agriculture Organization and a report author. "We do see payment for carbon sequestration. Carbon markets are becoming an increasingly common phenomenon," he says. "We do see biodiversity conservation payments taking place, but in a very few countries, but that is something that could be expanded even further."
UN agencies - which commissioned the report - have already begun to make decisions based on its findings. But Walter Reid says getting governments to adopt its policy proposals may take more time, although he notes, some countries have already begun the process. "China is being very responsive to this," he says. "They are about to launch a national assessment looking at ecosystem flows and values. Some of the Scandinavian countries are focusing a great deal of attention on this. We have heard that the Netherlands has incorporated it in a set of policy choices that they have made. But for many of the developed countries, we don't see perhaps as much as we would like, and for many of the developing countries I think the key thing is even if they would like to adopt this type of approach, they don't have the capacity to do it, and so that is where the international institutions really need to play a role in helping."
Reid hopes that the Millennium Ecosystem Assessment will inspire policy makers around the globe to more carefully map the world's ecosystems and more accurately measure their social and economic value - and to craft policies that, ultimately, will enhance both human health and the life of the planet.