Ecological Forecasting

This article makes the case that ecological forecast "could spell the difference between helpless reaction to environmental changes and dynamic action to head off catastrophes".

RIC comments:  Information can be used in many ways, and more information will not by itself enable us to avoid catastrophes. So long human baings fail to respect for natural forces, the basic trends will remain the same. Accurate ecological predictions will simply be used to develop strategies designed appease peoples' concerns, rather than to stop the behaviour that is causing the problem in the first place.

Ecological Forecasting Sheds Light on Planet's Future

By Cat Lazaroff

WASHINGTON, DC, February 23, 2000 (ENS) - A new breed of scientist may soon catch the attention of lawmakers around the world. Ecological forecasters, who project the effects that human activities may have on the environment, could spell the difference between helpless reaction to environmental changes and dynamic action to head off catastrophes before they have a chance to build.

Vanishing species, denuded landscapes and polluted waterways tell the familiar tale - the growing human population is exerting an increasing influence on the natural world. Demographers predict that the human population, already standing at more than six billion, may expand by another two to three billion by 2050.

Meanwhile, economists predict that the global economy, measured by the per capita gross domestic product, will likely triple by 2050. That economic growth represents the consumption of natural resources - for food, fresh water, space and trade goods. And the more that humans consume, the less is available for other species.

"It's a daunting task to try and forecast what the world might be like," said researcher David Tilman, an ecologist at the University of Minnesota. On Sunday, at a symposium organized by Tilman for the 2000 meeting of the American Association for the Advancement of Science (AAAS), a group of nascent environmental forecasters tackled some possible scenarios for the not too distant future - the world of 2050.

"[Humans] are such a major force now that we would assert it is no longer appropriate to allow decision making without this kind of foresight," said Tilman. No longer are human impacts as straightforward as bulldozed wetlands or toxic waste dumps, he argues. Because of such huge numbers of people on Earth, even the simplest actions of humanity have wide ranging repercussions.

Nearly everything that humans eat, for example, now comes from agriculture performed on a monumental scale. In order to meet the needs of a growing population, agricultural research turned to increasing the yield and efficiency of cropland. Over the past 35 years, food production has doubled.

But associated with this successful agricultural transformation - often called the Green Revolution - is a 6.8 fold increase in the amount of nitrogen used to fertilize fields. When that nitrogen runs off of fields into waterways, it can cause enormous algae blooms. When the algae dies, the resultant decay consumes most of the oxygen in the water, suffocating fish and other marine creatures.

"High nitrogen is an evolutionary oddity for the world," notes Tilman.

On land, Tilman and others have shown that excess nitrogen from fertilized fields can be deposited onto nearby fields. Increasing the nitrogen available in the soil offers an edge to some weeds, which have evolved to take advantage of normally rare periods of abundant nitrogen. The rapidly growing weeds, which are often invaders from other ecosystems, can overwhelm native species and leave a nearly sterile sea of a single plant species.

To sustain another doubling in agricultural yields, which would be necessary to feed the projected population growth by 2050, Tilman estimates that nitrogen fertilization would probably have to triple. Unless crops and agricultural techniques that need less fertilization are developed, and their use becomes widespread, excess nitrogen will pose a serious threat to biodiversity, Tilman warns. He hopes that lawmakers will take steps now to boost investment in the research and development of less nitrogen intensive agricultural methods.

Other factors that could limit the world’s ability to produce enough food for the growing population are diminishing supplies of arable land and fresh water. Andy Dobson, a professor in Princeton University’s Ecology and Evolutionary Biology department, noted that if current trends continue, the world would need to increase the amount of irrigated land used to grow crops by 98 percent by 2050. However, irrigation already uses about 50 percent of the fresh water available, he said. Doubling irrigation would use up all remaining freshwater reserves, Dobson warned.

In order to create enough crop and pastureland to double the world’s food supply, about 8.8 million hectares of land would need to be converted for agriculture, Dobson said - about the same area of the entire United States. As most of the world’s readily arable land is either already in production or covered by cities, it may be impossible to find enough suitable land.

Cutting down the rainforests would not create good farmland, he noted, as the ground beneath these forests is too poor to support more than a couple of years of farming. Unless steps are taken now to find alternative means of food production that do not require huge expansions in land and irrigation, Dobson warned that it may not be possible for governments to develop food resources fast enough to feed future generations.

Another effect of population growth that could threaten the food supply - and biodiversity - is invasions by nonnative species. The United States alone loses about $136 billion each year to invasive species, through crop and timber losses, and the costs of controlling their spread.

Experts estimate that at least 50 percent, and up to 70 percent, of declining and vanishing species may be linked to invasive species that out-compete, infect or devour native species. "Not a very large percentage of our threatened and endangered species are recovering," said Carla D'Antonio, associate professor of integrative biology at the University of California, Berkeley. "A lot of them will probably go extinct."

About 80 percent of invasive species arrive through some form of international trade. Asian gypsy moths may travel on the outsides of cargo containers. Asian longhorned beetles, which now cost the U.S. millions of dollars in damages to trees from New York to Boston, arrived in the wooden pallets surrounding rocks imported from China.

"Trade, we believe, is the most significant source of harmful invasive species, and it is increasingly exponentially," said D’Antionio. "Even if we shut the gates today … we’re still going to see for the next 50 years" the effects of the exotic species that are already established in the U.S.

"We obviously can't get rid of trade, but we have to make a commitment to inspection, quarantine and control to accompany the rise" in trade, D'Antonio said. "The first place to stop these exotic species is at the dock, or even better, before they leave their native country."

Investing now in programs to prevent the export and import of these unwanted stowaways would save billions in control costs, crop losses and reduced biodiversity later, said D'Antonio. Some of that investment could come from industries that profit most from trade, like shipping, she said.

"To date, the people who pay the costs have never been the people who caused the invasion in the first place," said D'Antonio.

Within the U.S., biodiversity is also increasingly threatened by the fragmentation of lands by roads and power lines, said Dobson. Today, America has 2.66 million miles of paved roads and 375,000 miles of power lines, he said. By 2050, the mileage of roads is expected to jump 138 percent, and power line construction is expected to rise by 122 percent.

The panelists noted that these issues will become increasingly difficult to solve over time. Through ecological forecasting, governments and other decision makers could begin to decide now how best to confront the challenges of the next 50 years. But they were not optimistic about their ability to win over the world’s power brokers.

"We used the word forecasting because it reminded us of meteorology - which no one believes anyway," Tilman said.

Source: February 23, 2000 (ENS)