No need to wait for the clean air dividend 20/04/2012, 12:32:34 AM (GMT+7)

(Newscientist)-Controlling smog and soot is the classic win-win situation, so it’s great that the world is finally waking up to the idea.

<i>(Image: Andrzej Krauze)</i>
(Image: Andrzej Krauze)

WHAT if there was a way to simultaneously slow down climate change, save millions of lives, improve crop yields and contribute to sustainable development and energy security? It sounds too good to be true, but it is possible. It won't be free or easy, but with some effort and moderate investment, it can be done.

The way to do it is to reduce emissions leading to two types of pollution: black carbon and ozone. These are the only pollutants that we know contribute to both global warming and poor air quality.

Black carbon is essentially soot, emitted from incomplete combustion of fossil fuels and biomass. It warms the climate in two ways: by absorbing heat in the atmosphere - similar to the greenhouse effect - and by reducing Earth's albedo, or ability to reflect sunlight. Inhaled into the lungs, it leads to cancer and cardiovascular disease.

Ozone in the atmosphere also acts as a greenhouse gas, while ground-level ozone is toxic to humans and plants, so leads to both premature death and reduced crop yields. Ozone is not emitted directly but is produced by the action of sunlight on other pollutants, which are known as ozone precursors.

Since black carbon and ozone are important components of soot and smog, a great deal of effort has already been put into developing methods to reduce emissions. So effective technology is available, but needs wider implementation.

The recommended control measures for black carbon include widespread and tight emission standards on diesel cars and trucks; improved solid fuel cooking stoves, brick kilns and coke ovens in the developing world; and a ban on the open burning of agricultural waste.

Implementation of these measures would have a rapid impact on the climate and human health, and also have the added benefit of greatly reducing emissions of carbon monoxide, an important ozone precursor.

A second key ozone precursor is methane, which is also a powerful greenhouse gas in its own right. Control measures include reducing leaks from natural gas pipelines and storage tanks, and capturing it from coal, gas and oil extraction, landfills and wastewater treatment plants. Aeration of rice paddies and manure management can also reduce methane releases.

Captured methane can often be sold or turned into power. In Monterrey, Mexico, for example, electricity generated from methane collected from the city landfill powers the public transportation system. So such measures can be beneficial even when ignoring the health and climate effects, as they can contribute to energy security and often pay for themselves.

According to calculations by me and my colleagues, phasing in all these measures over the next 20 years would reduce global warming by about 0.5 °C in 2050, half of the projected increase between now and then (Science, vol 335, p 183).

Regional benefits would be even greater, as black carbon disrupts rainfall patterns and magnifies warming and melting of snow and ice in parts of the world including the Arctic and the Himalayas.

On top of the climate benefits, cutting black carbon and ozone would prevent over 3 million premature deaths from air pollution, and increase yields of staple crops by roughly 50 million tonnes a year.

Improved cooking stoves would also decrease the demand for firewood in the developing world, reducing deforestation and freeing up time for those who collect wood - primarily women and children - to pursue other activities such as education.

Similarly, improved brick kilns now being used in parts of Latin America and Asia require half as much fuel as traditional ones and are less time-intensive for the operators. This means that in addition to their environmental benefits, these measures can contribute to sustainable and human development.

Tackling black carbon and methane is clearly a great idea, so why hasn't it been done already? There are many barriers. The upfront costs of some measures can be prohibitive even when they eventually pay for themselves. But this can be overcome by mechanisms such as international financing of capital costs.

For other measures, the costs are typically borne by a few while the benefits accrue to everybody. In such cases civil society and governments must get involved.

Governments are starting to act. In February, the US, Canada, Sweden, Bangladesh, Ghana and Mexico launched the Climate and Clean Air Coalition to support implementation of measures like these. This coalition will hopefully expand and achieve rapid, widespread adoption of measures to cut black carbon and ozone.

While the climate benefits will be substantial, it is important to note that these measures cannot substitute for cuts in carbon dioxide. Black carbon, ozone, carbon monoxide and methane stay in the atmosphere for a fairly short time - a few days for black carbon and about a decade for methane. They thus respond quickly to emissions changes and give us substantial leverage over near-term climate change.

In contrast, carbon dioxide is very long-lived and so responds slowly to emissions changes. This means that cuts have little immediate impact, but it also means they must be made now to avoid disastrous changes later on.

Controlling short-lived climate pollutants is thus an issue of fairness. Much as failure to reduce carbon dioxide emissions soon would condemn future generations to disastrous change, failure to reduce near-term climate change condemns those alive today to suffer worsening effects of the sort already seen.

Asian air pollution strengthens Pacific storms WHO: air pollution 'is single biggest environmental health risk' Does Paris have worse air pollution than Beijing Without clean air, we have nothing Dust can affect planet's climate
Other News
Parisians driven to revolt by car ban in fight against pollution European Commission sues UK over polluted air China's toxic air pollution resembles nuclear winter Vietnam warned of severe air pollution Air pollution: European commission launches legal action against the UK Air pollution from Asia affecting world's weather China looks to snuff out New Year fireworks to combat air pollution Beijing's mayor announces 'all-out effort' to tackle air pollution Binh Thuan titanium land: miners get ore, people get dust China sets air pollution goals
Regional cooperation needed in climate change adap 23/04/2014, 12:31:05 PM (VNA)-Regional cooperation constitutes an effective solution to coping with climate change and rising sea levels in Vietnam, a symposium in Hanoi heard on April 22.
Mekong River nations urged to drop 11 hydropower p 23/04/2014, 12:29:54 PM (SGT)-The Save the Mekong Coalition has written to the government leaders of the nations in the Mekong River basin to cancel 11 hydropower projects in the Lower Mekong mainstream, saying the dams could impact on the environment, natural recourses, aquatic life and ecological balance of the basin.
The unique animals of U Minh Thuong 23/04/2014, 12:28:55 PM On August 12, 2013, U Minh Thuong National Park (Kien Giang Province) was awarded an ASEAN Heritage Park certificate.
Illegally logged timber carried day and night acro 22/04/2014, 12:43:57 PM (VietNamNet Bridge)-Illegal loggers and timber traders now can easily escape the foreign rangers’ notice and carry illegally cut wood in broad daylight.
Phu Yen's "Village of lost teeth" 22/04/2014, 12:41:18 PM (ANTD, dtinews)-Nearly everyone in a village in the central province of Phu Yen suffer from severe dental problems leading eventually to tooth loss, and they blame it on the water source.
Most viewed
Illegally logged timber carried day and night across check-points 22/04/2014, 12:43:57 PM (VietNamNet Bridge)-Illegal loggers and timber traders now can easily escape the foreign rangers’ notice and carry illegally cut wood in broad daylight.
Con Dao National Park named a world Ramsar site 21/04/2014, 12:41:52 PM (VietNamNet Bridge)-With an environment favorable for the conservation of such marine species as sea turtle, dolphin and dugong, Con Dao mangrove forest has been recognized as a Ramsar site of the world.
Corn biofuels worse than gasoline on global warming in short term 21/04/2014, 12:33:36 PM (Theguardian)-Biofuels made from the leftovers of harvested corn plants are worse than gasoline for global warming in the short term, a new study shows, challenging the Obama administration's conclusions that they are a much cleaner oil alternative and will help combat climate change.
Phu Yen's "Village of lost teeth" 22/04/2014, 12:41:18 PM (ANTD, dtinews)-Nearly everyone in a village in the central province of Phu Yen suffer from severe dental problems leading eventually to tooth loss, and they blame it on the water source.
Researchers rethink 'natural' habitat for wildlife 21/04/2014, 12:34:49 PM (Sciencedaily)-Protecting wildlife while feeding a world population predicted to reach 9 billion by 2050 will require a holistic approach to conservation that considers human-altered landscapes such as farmland, according to Stanford researchers.
© Copyright 2007-2011 Vfej.vn
Designed and developed by Ovem!Software
Management Agency: Vietnam Forum of Environmental Journalists
Address: 22/A2, Lane 49, Linh Lang Street, Ba Dinh District, Hanoi-Vietnam
Tel: (84-4) 37628933 - Fax: (84-4) 37628933
Publishing License: No. 513/GP-BC issued on 22/11/2007