The hidden benefits of climate policy: Reducing fossil fuel use saves lives now

Much of the debate over global climate policy misses one basic point: The same activities that will eventually threaten the earth's climate also threaten human health today. The combustion of fossil fuels poses a double jeopardy. It produces carbon dioxide and other gases, which contribute to the gaseous greenhouse that warms the earth, and it releases fine air-borne particles, which can make people sick and damage their lungs.

The first study ever to look at the global short-term health impact of fossil fuel consumption projects significant consequences for people's health and mortality worldwide. (See chart 1.) This study by the Working Group on Public Health and Fossil-Fuel Combustion,[1] finds:

• Air pollution from fossil fuel use has immediate local and global impacts on public health, because fine air-borne particles can move hundreds or thousands of kilometers to sicken or kill people.

• The benefits of reducing CO2 emissions go substantially beyond averting potential disruptions of the Earth's climate. Even relatively small reductions in emissions worldwide could prevent 700,000 premature deaths a year by 2020.

• The benefits of adopting climate policies extend to both developed and developing nations. Four out of every five of those who might otherwise die by 2020 are in developing countries. In the developed world, the number of lives potentially saved each year is also substantial, equaling the number projected to die from traffic injuries.

• Implementing climate policies now will yield immediate benefits locally and globally by reducing particulate air pollution, by slowing the build-up of greenhouse gases, and by protecting public health. Over the next two decades, at least 8 million deaths could be avoided.

Particulates and health

The study focuses on the health consequences of particulate matter, the solid or liquid particles found in the air. Particles can originate from a variety of mobile, stationary, and natural sources, including power plants, diesel trucks, wood stoves, and dust from roads.

The chemical and physical composition of particulates varies widely. Most of the smallest particles result from burning fossil fuels. These small particles can remain aloft for days, even weeks, and can travel thousands of kilometers. For example, researchers at the National Oceanic and Atmospheric Administration's station at Mauna Loa Observatory have tracked carbon particulates to Hawaii from specific smokestacks in Beijing.[2]

Particulates pose a major hazard for human health. The adverse effects have been traced mainly to small particles with an aerodynamic diameter of 10 microns or less, which can reach deep into the lungs. Smaller particles can go even deeper into the lungs, where those that are still tinier can enter the blood stream. These particles can disturb the lungs physically and chemically. They can directly irritate the lungs, and they can carry toxic heavy metals and other pollutants.

The average person breathes several million liters of air a year. Children take in even more air relative to their body weight and size. Those who exercise heavily or work hard, of course, breathe even greater volumes of air. Breathing finely polluted air can produce slow and insidious effects or devastating and immediate ones. Over a lifetime, regular breathing of contaminated air can impede the ability of the lungs to breathe in oxygen and get rid of pollutants. Polluted air can cause immediate or acute effects ranging from asthma attacks to death in those whose lungs are already weakened.

Two climate scenarios

The study compares the health consequences from particulate air pollutants under two climate scenarios: the "business-as-usual" scenario and a hypothetical "climate policy" scenario. Both scenarios assume that energy use and energy efficiency in the developing countries continue to increase to meet the needs of economic growth. The two scenarios differ in their assumed rates of growth in energy use, in projected changes in fuel mix, and in their assumptions about combustion and end-use efficiencies. Particulate emissions and concentrations globally are calculated by applying models of U.S. air pollution to other regions.

The "business-as-usual" scenario updates the 1992 analysis by the Intergovernmental Panel on Climate Change of expected trends in energy consumption and associated CO2 emissions.[3] The "climate policy" scenario assumes that developed countries would reduce energy-related CO2 emissions 15 percent below 1990 levels by the year 2010, in compliance with the target proposed by the European Union. Developing countries are assumed to achieve emissions 10 percent below what they would otherwise be by the year 2010. Although developing countries have not set this target specifically, they have generally agreed to undertake actions to increase their fuel efficiency and reduce their emissions of CO2 per unit of energy produced.

Comparing the projections

CO2 emissions now are about 1 ton per person each year, with 25 percent of the total produced by 5 percent of the world's population. Under the business-as-usual scenario, CO2 emissions in developed nations would rise by about 17.5 percent during 1990-2020. (See chart 2.) This relatively moderate rate of growth is partly explained by the recent drop in energy consumption in nations formerly in the Soviet Union. In this region, energy consumption is not expected to reach 1990 levels by the year 2020. For developed nations as a whole, fossil fuel consumption is expected to rise from 209 EJ (1018 joules) to 239 EJ, and CO2 emissions to rise from 4 BMTC (billion metric tons of carbon) in 1990 to 4.7 BMTC in 2020.

Chart 2	Fossil fuel use in developing and developed countries

In developing nations, energy consumption over the 1990-2020 period is expected to triple under the business-as-usual scenario, rising from 91 to 316 EJ. CO2 emissions are expected to increase from 1.9 BMTC to 6 BMTC, or about 216 percent over the 30-year period.

Under the climate policy scenario, fossil fuel use would decline by about 6 percent in the developed countries compared with the 1990 baseline and by about 18 percent compared with business-as-usual in 2020. CO2 emissions would decline to 3.4 BMTC, a 15 percent decline from 1990 levels and a 28 percent decline compared with business-as-usual in 2020. In developing nations, the climate policy scenario would result in a 9 percent decline in fossil fuel use and a 10 percent decline in CO2 emissions compared with business-as-usual in 2020.

Health impact

By 2020, adoption of the climate policy scenario could avoid at least 700,000 premature deaths annually as a result of reduced particulate pollution. This includes about 563,000 deaths each year in developing countries and 140,000 in developed countries. (See chart 3.)

Chart 3	Lives potentially saved annually from climate policies

The cumulative effect of these savings is enormous. From 2000 to 2020, adoption of climate policies could avoid a total of 8 million deaths globally, including about 6.3 million in developing countries and 1.7 million in developed countries. (See chart 4.) The potential for saving lives is much higher in developing countries than developed ones because, under the climate policy scenario, the expected change in particulate concentrations is much higher in the developing world.

Chart 4	Lives potentially saved cumulatively from climate policies

China dramatically illustrates the potential health risks facing developing countries in the absence of climate policies. A recent World Bank study estimates the health costs of exposure to particulates for urban residents in China.[4] Under a business-as-usual scenario the health costs will rise from $32 billion (or $129 per resident exposed) in 1995 to nearly $98 billion (or $197 per resident exposed) in 2020. The costs include 600,000 premature deaths, 5.5 million cases of chronic bronchitis, more than 5 billion restricted- activity days, and 20 million cases of respiratory illness each year. When adjusted to the projected increases in income, the costs in 2020 will total more than $390 billion, or 13 percent of gross domestic product (GDP).

From 2000 to 2020, adoption of climate policies could avoid a total of 8 million deaths globally.

The health implications of adopting climate policies are not confined to developing countries, however. In developed countries, deaths tied with particulate air pollution rank among the top ten causes of death, according to estimates prepared by the World Health Organization.[5] In the United States alone, the potential number of lives saved annually by reducing particulates is equal to the number of deaths that occurred last year from HIV or infectious liver diseases.

Because the study followed a conservative approach, the benefits may be far greater than those estimated. For example, estimates include only avoidable deaths among adults more than 30 years old and infants less than one year old. In addition, by focusing only on deaths that could be avoided by reducing particulates, the study did not estimate health benefits less dramatic -- but much greater overall -- such as avoidable illness and days lost from work. Nor did it consider deaths associated with pollutants other than particulates.

A global problem

Particulate air pollution associated with the burning of fossil fuels does not stay within national boundaries, nor are its effects limited to any one region or income group. Thus, dangerously high levels of fine particulate air pollution generated by the forest fires of Borneo this summer have been found in Southeast Asian cities hundreds of kilometers away. Bad air quality and visibility associated with those fires was severe enough to cause the evacuation of dependents at the U.S. embassy in Kuala Lumpur and to be a contributing factor in serious airline and shipping accidents.

But, just as rich and poor countries alike contribute to the problem, they both benefit from the solution. Stemming the rise in particulate emissions is particularly significant for the emerging megacities in the developing world, where unprecedented numbers of people may be exposed to significant risks from air pollution. Nonetheless, the incremental benefit from reducing particulate air pollution may be substantial in richer countries, because their population faces fewer risks from other health problems, such as malnutrition and infectious diseases. Even if environmental factors pose relatively small risks, reducing air pollution can significantly improve public health, wherever exposure is universal and the population is vulnerable.

The need for a global solution

Both developed and developing countries have clear and compelling reasons to adopt policies that reduce greenhouse gas emissions now by increasing energy efficiency and encouraging the use of less carbon-intensive fuels. Any reduction in CO2 emissions from fossil fuel use will yield immediate benefits locally and globally by reducing particulate air pollution, by slowing the build- up of greenhouse gases, and by protecting the lives of millions of people.

These predictions and others made in the study are at best partial estimates of likely consequences that will occur worldwide, if business-as-usual continues in the absence of a concerted effort to develop global climate policies. This study was restricted to particulate concentrations, yet a climate change agreement could provide significant reductions in other conventional pollutants, including hazardous organic compounds and heavy metals, such as lead and mercury. An important next step is to calculate the health benefits that will arise from reducing these pollutants as well.

With the complex issues posed by climate change, one of the major challenges is to learn from the present and the past in order to predict the future. The analysis presented by the Working Group is not intended to be a precise prediction, but a broad forecast of the magnitude of health consequences under different climate scenarios. This forecast provides a clear signal that fossil fuel emissions are a global problem, not merely a local one. It also clearly signals hope, if concerted action is taken: relatively small reductions in carbon emissions over the next two decades can yield big benefits to public health worldwide.

The cross-disciplinary approach pursued in the study estimates potentially far-ranging and substantial health impacts in an uncertain future world. It recognizes that the health of the population in any region reflects an intricate combination of factors, including poverty, nutrition, population density, housing, sanitation, smoking, working conditions, and the environment. Although the environmental factors cannot account for all these patterns, they are important because they can be changed by public policy.

Adopting climate policies now will turn the double jeopardy of fossil fuel emissions into a double play. By reducing emissions, we will lessen the build-up of greenhouse gases and save hundreds of thousands of lives worldwide.