2009年11月18日星期三

Climate change

Climate change endangers health in fundamental ways. The warming of the planet will be gradual, but the effects of extreme weather events – more storms, floods, droughts and heatwaves – will be abrupt and acutely felt. Both trends can affect some of the most fundamental determinants of health: air, water, food, shelter, and freedom from disease.
Climate change is a significant and emerging threat to public health, and changes the way we must look at protecting vulnerable populations.
The most recent report of the Intergovernmental Panel on Climate Change confirmed that there is overwhelming evidence that humans are affecting the global climate, and highlighted a wide range of implications for human health. Climate variability and change cause death and disease through natural disasters, such as heatwaves, floods and droughts. In addition, many important diseases are highly sensitive to changing temperatures and precipitation. These include common vector- borne diseases such as malaria and dengue; as well as other major killers such as malnutrition and diarrhoea. Climate change already contributes to the global burden of disease, and this contribution is expected to grow in the future.
Although climate change is a global phenomenon, the impacts of climate on human health will not be evenly distributed around the world. Developing country populations, particularly in Small Island States, arid and high mountain zones, and in densely populated coastal areas, are considered to be particularly vulnerable.
Climate change can no longer be considered simply an environmental or developmental issue. More importantly, it puts at risk the protection and improvement of human health and well-being. A greater appreciation of the human health dimensions of climate change is necessary for both the development of effective policy and the mobilization of public engagement.
Fortunately, much of the health risk is avoidable through existing health programmes and interventions. Concerted action to strengthen key features of health systems, and to promote healthy development choices, can enhance public health now as well as reduce vulnerability to future climate change.

What should we do to reverse Climate Change?


The enormity of global warming can be daunting and dispiriting. What can one person, or even one nation, do on their own to slow and reverse climate change?
Forego Fossil Fuels—The first challenge is eliminating the burning of coal, oil and, eventually, natural gas. This is perhaps the most daunting challenge as denizens of richer nations literally eat, wear, work, play and even sleep on the products made from such fossilized sunshine. But we have to try to employ alternatives when possible—plant-derived plastics, biodiesel, wind power—and to invest in the change, be it by divesting from oil stocks or investing in companies practicing carbon capture and storage.
Infrastructure Upgrade—Buildings worldwide contribute around one third of all greenhouse gas emissions (43 percent in the U.S. alone), even though investing in thicker insulation and other cost-effective, temperature-regulating steps can save money in the long run. energy-efficient buildings and improved cement-making processes (such as using alternative fuels to fire up the kiln) could reduce greenhouse gas emissions in the developed world and prevent them in the developing world.
Move Closer to Work—Transportation is the second leading source of greenhouse gas emissions in the world. One way to dramatically curtail transportation fuel needs is to move closer to work, use mass transit, or switch to walking, cycling or some other mode of transport that does not require anything other than human energy. There is also the option of working from home and telecommuting several days a week.
Consume Less—The easiest way to cut back on greenhouse gas emissions is simply to buy less stuff. Whether by forgoing an automobile or employing a reusable grocery sack, cutting back on consumption results in fewer fossil fuels being burned to extract, produce and ship products around the globe.Think green when making purchases and when purchasing essentials, such as groceries, buying in bulk can reduce the amount of packaging—plastic wrapping, cardboard boxes and other unnecessary materials. Sometimes buying more means consuming less.
Be Efficient—A potentially simpler and even bigger impact can be made by doing more with less. Citizens of many developed countries are profligate wasters of energy, whether by speeding in a gas-guzzling sport-utility vehicle or leaving the lights on when not in a room. Employing more efficient refrigerators, air conditioners and other appliances can cut electric bills while something as simple as weatherproofing the windows of a home can reduce heating and cooling bills. Such efforts can also be usefully employed at work, whether that means installing more efficient turbines at the power plant or turning the lights off when you leave the office.
Eat Smart, Go Vegetarian—University of Chicago researchers estimate that each meat-eating American produces 1.5 tons more greenhouse gases through their food choice than do their vegetarian peers. It would also take far less land to grow the crops necessary to feed humans than livestock, allowing more room for planting trees.
Stop Cutting Down Trees—Every year, 33 million acres of forests are cut down. Timber harvesting in the tropics alone contributes 1.5 billion metric tons of carbon to the atmosphere. That represents 20 percent of human-made greenhouse gas emissions and a source that could be avoided relatively easily. Improved agricultural practices along with paper recycling and forest management—balancing the amount of wood taken out with the amount of new trees growing—could quickly eliminate this significant chunk of emissions.
Unplug—Televisions, stereo equipment, computers, battery chargers and a host of other gadgets and appliances consume more energy when seemingly switched off, so unplug them instead. Purchasing energy-efficient gadgets can also save both energy and money—and thus prevent more greenhouse gas emissions. To take but one example, efficient battery chargers could save more than one billion kilowatt-hours of electricity—$100 million at today's electricity prices—and thus prevent the release of more than one million metric tons of greenhouse gases.
One Child—More humans means more greenhouse gas emissions. There are at least 6.6 billion people living today, a number that is predicted by the United Nations to grow to at least nine billion by mid-century. The U.N. Environmental Program estimates that it requires 54 acres to sustain an average human being today—food, clothing and other resources extracted from the planet. Continuing such population growth seems unsustainable. Falling birth rates in some developed and developing countries (a significant portion of which are due to government-imposed limits on the number of children a couple can have) have begun to reduce or reverse the population explosion. It remains unclear how many people the planet can comfortably sustain, but it is clear that per capita energy consumption must go down if climate change is to be controlled.
Future Fuels—Replacing fossil fuels may prove the great challenge of the 21st century. Many contenders exist, ranging from ethanol derived from crops to hydrogen electrolyzed out of water, but all of them have some drawbacks, too, and none are immediately available at the scale needed. Massive investment in low-emission energy generation, whether solar-thermal power or nuclear fission, would be required to radically reduce greenhouse gas emissions. And even more speculative energy sources—hyperefficient photovoltaic cells, solar energy stations in orbit or even fusion—may ultimately be required.
The solutions above offer the outline of a plan to personally avoid contributing to global warming. But should such individual and national efforts fail, there is another, potentially desperate solution:
Experiment Earth—Climate change represents humanity's first planetwide experiment. But, if all else fails, it may not be the last. So-called geoengineering, radical interventions to either block sunlight or reduce greenhouse gases, is a potential last resort for addressing the challenge of climate change.
Among the ideas: releasing sulfate particles in the air to mimic the cooling effects of a massive volcanic eruption; placing millions of small mirrors or lenses in space to deflect sunlight; covering portions of the planet with reflective films to bounce sunlight back into space; fertilizing the oceans with iron or other nutrients to enable plankton to absorb more carbon; and increasing cloud cover or the reflectivity of clouds that already form.
All may have unintended consequences, making the solution worse than the original problem. But it is clear that at least some form of geoengineering will likely be required: capturing carbon dioxide before it is released and storing it in some fashion, either deep beneath the earth, at the bottom of the ocean or in carbonate minerals. Such carbon capture and storage is critical to any serious effort to combat climate change.

Reference:
1.Climate Action Network Australia : Solutions to climate change
http://www.cana.net.au/bush/solutions.htm(visited in 13.11.09)
2.Stop climate change http://www.greenpeace.org/international/campaigns/climate-change(visited in 13.11.09)
3.Ten solution for climate change http://www.scientificamerican.com/article.cfm?id=10-solutions-for-climate-change&page=4(visited in 13.11.09)
4. WHO, Protecting health from climate change top 10 actions for health professionals
5. WTO, Climate change is affecting our health_ something should be done now

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