Rapid environmental change threatens human health: Worldwatch

Washington: Changes to the earth's land cover, climate and ecosystems are endangering the health of hundreds of millions, possibly over a billion, of people worldwide and now represent the greatest public health challenge of the 21st century, says international green think tank Worldwatch Institute.




The scale of these global changes is rapidly undermining human life-support systems and threatening the core foundations of healthy communities around the globe.

Access to adequate food, clean air, safe drinking water, and secure homes are all affected, a Worldwatch spokesperson said here Thursday while releasing a new report, Global Environmental Change: The Threat to Human Health.

Published by Worldwatch and the United Nations Foundation, the report notes that, as a result of rapid changes to the climate and in land use, we are already seeing alterations in the distribution of malaria, schistosomiasis, and other infectious diseases in many regions.

It concludes that poor populations, mainly in developing countries, are the most vulnerable to these environmental changes, even though they are the least responsible for contributing to these.

"It is increasingly apparent that the breadth and depth of the changes we are wreaking on the environment are imperiling not only many of the other species with which we share the ecological stage, but the health and wellbeing of our own species as well," writes the report's author Samuel S. Myers of Harvard Medical School and Research Associate at the Harvard University Center for the Environment.



The report outlines a series of public health threats -- food and water inscarcity, altered distribution of infectious diseases, increased air pollution, natural disasters, and population displacement -- that collectively threaten large segments of the human population.

But most of the death and disability from these threats is fundamentally preventable, Myers writes, if the political will can be mobilised to take strong, concerted action.

The report outlines the need for national-level risk assessments to identify the greatest threats in different regions, as well as unprecedented technical and financial assistance from the international community to help developing countries adapt to the health impacts of accelerating environmental change.

Ultimately, the report argues, we will need to find new ways to generate economic growth that do not cause serious ecological deterioration, or the progress that has been made toward global health, nutrition, and poverty alleviation will be undone.

"At present, all of the major types of human caused environmental change -- climate change, changes in land use and cover, and ecosystem service degradation -- are accelerating," Myers says.

"To reduce the avoidable human suffering that will result, we must redouble our efforts to slow the pace of environmental change, reduce the rate of human population growth, and reduce the vulnerabilities of those in harm?s way."

Source: IANS

World’s major rivers under threat from environmental stressors

New Delhi: Multiple environmental stressors such as agricultural runoff, pollution and invasive species threaten the world's major rivers that serve 80 per cent of the world's population, a new research report has warned.




Between them, these rivers provide water to over 5 billion people who live near them, besides providing a home to thousands of species.

These stressors endanger the biodiversity of 65 per cent of the world's river habitats and put thousands of aquatic wildlife species at risk. Also, over-development and excessive extraction as well as billions of dollars of investment by developed countries to avert water stress have damaged biodiversity of the rivers, the report published in the latest issue of journal Nature said.



The findings of the report follow the first global-scale initiative to quantify the impact of multiple stressors on humans and riverine biodiversity. The research team comprised scientists and experts from The City College (CCNY) of The City University of New York (CUNY), University of Wisconsin and seven other institutions.

The team produced a series of maps documenting the impact using a computer-based framework they developed.



"We've integrated maps of 23 different stressors and merged them into a single index," said the report's lead author Peter McIntyre of University of Wisconsin-Madison. "In the past, policymakers and researchers have been plagued by dealing with one problem at a time. A richer and more meaningful picture emerges when all threats are considered simultaneously", he added.

Rivers in some of the world's most populated regions, including Yellow River in northern China, Ganges in India, Niger in West Africa, are losing water largely due to climate change.



Experts have warned that the changes taking place could threaten food and water supply of millions of people who live in some of the world's poorest regions.

The report stated that over 30 of the world's 47 largest rivers, which collectively account for half of the global runoff of freshwater, are under at least "moderate" threat. Eight of them are rated as being under very high threat in terms of water security for humans while 14 are rated as being under very high threat for biodiversity.



What's worse is that the report said the estimates arrived at by the research team are most probably conservative as it was unable to take into account pollution from mining or the effects on biodiversity from rising levels of pharmaceutical products in river water.

At the same time, the report stated that some rivers were not yet threatened. The rivers of Scandinavia, Siberia, northern Canada and unsettled parts of the tropical zone in Amazonia and northern Australia have the lowest threat rating.

In rich countries, heavy investment in dams and reservoirs and diverting flows from wetlands has benefited 850 million people, reducing their exposure to extreme water scarcity by 95 per cent, the report said.



The team noticed that rivers in different parts of the world were subject to similar types of stresses -- whether they were present in a developed or developing country -- such things as agricultural intensification, industrial development, river habitat modification and other factors.

"Flowing rivers represent the largest single renewable water resource for humans," said Charles J. Vörösmarty of the City University of New York, one of the report's co-authors. "What we've discovered is that when you map out these many sources of threat, you see a fully global syndrome of river degradation."

Source: India Water Review