Environmental Threats

The expansion of human activity and associated loss of habitat are the leading causes of the unprecedented extinctions of plant and animal species worldwide. The loss of biological diversity leads to instability of ecological systems, particularly those that are stressed by climate change or invasion of non-native species.

Massive rural to urban migration in much of the developing world has overwhelmed water treatment systems, resulting in water pollution that leads to intolerable health conditions for many people.

Despite this migration, rural populations are also growing, leading to overuse of land and resultant erosion of hillsides and silting of rivers, as typified by Madagascar, Nepal and Haiti.
The same pressures are hastening the destruction of vast forest areas and loss of wildlife habitat. The loss of forests also reduces the ability of the ecosystem to combat global warming. Carbon dioxide that would be absorbed by trees instead stays in the atmosphere.
On a global basis, emissions of greenhouse gases, such as carbon dioxide, are rising rather than falling, despite the international agreements designed to reduce emissions. Given this trend, many scientists believe that global warming will accelerate during this century, with consequences including rising sea levels, growing weather severity, and disruption of agriculture.

Greenhouse gas emissions are increasing in developing countries, where populations are expanding most rapidly. In some of these countries, energy consumption and production of greenhouse gases is rising on a per capita basis as the countries' economies expand. In most, there is an understandable desire to increase living standards by increasing production and per capita consumption of energy and resources. Median projections of expanding economic activity in developing countries indicate that the developing world will be producing more greenhouse gases than the developed countries by the year 2020. At the same time, the developed countries are generally failing to make progress on reduction of greenhouse gas emissions, in part because of continuing population increases, especially in the United States.

Given the trends in population, energy and resource consumption, combined with technological innovations, the adverse human impact on the global ecosystem could triple or quadruple by the year 2050.