Global warming and rising levels of pollution.
Rising levels of pollution may have also contributed to a wave of outbreaks of diseases affecting marine life.
Water pollution and water scarcity are burdening the economy, rising levels of air pollution are endangering the health of millions of Chinese, and much of the country's land is rapidly turning into desert.
In economically developing countries such as Brazil, India and China, rising levels of noise pollution are associated with the accelerated growth of cities and the increasing circulation of automotive vehicles.
Rising levels of air pollution in developing regions in South and East Asia largely drove the upward trend.
Together, climate change and rising levels of global pollution may amplify these risks.
Similarly, rising levels of larger-particulate air pollution (PM 10) were also linked to heart-attack risk.
The same power plants and vehicles responsible for rising levels of carbon dioxide contribute to ozone pollution too, and the new research finds that ozone aids insects and diseases that stunt the growth of trees and reduce their ability to soak up carbon dioxide (CO2).
However, overfishing threatens livelihoods, unmanaged aquaculture expansion can cause pollution and rising levels of carbon dioxide in the atmosphere contribute to ocean acidification.
According to the InterAcademy Panel Statement on Population Growth (1994), many environmental problems, such as rising levels of atmospheric carbon dioxide, global warming and pollution, are aggravated by population expansion.
The Environmental Ministry said the percentage of China's coastal waters rated at the worst possible level of pollution rose to 25.4percentt last year, from 24.3percentt a year earlier.
