Today, overwhelming scientific evidence has led to a consensus among scientists that climate change is real, is caused by human activities, and demands immediate action.

Scientists report a rise in carbon dioxide levels in the atmosphere and a subsequent rise in sea levels—caused by warming oceans that expand from absorbing carbon dioxide, not melting glaciers—as well as unusual swings in the global climate system. There have been droughts in some regions, bigger-than-usual storms in others.

The United States and other industrialized countries have begun to address climate change, but experts fear these actions may not be enough. More than 90 percent of carbon dioxide emissions growth from now until 2030 will come from the developing world, according to the International Energy Agency.

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Developing Countries will Suffer Most from Climate Change

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As the world’s largest aid donor to developing countries, the United States has worked for decades to boost economic growth and help these countries cope with the effects of climate change such as floods, famine, storms, drought, and the loss of grazing land and wildlife.

USAID also helps countries develop and adapt to climate change without emitting large amounts of greenhouse gases.

Political leaders, government delegates, scientists, and activists gathered in Copenhagen in December 2009 for annual international negotiations on climate change—a follow up to the 1997 Kyoto meeting that produced the first global effort to rein in greenhouse gases.

Indian women trained through a USAID program prepare mango bars using a solar-powered dryer unit. Solar dryers in India enable farmers to efficiently use energy to turn excess produce into food and income off-season.

As part of the Copenhagen Accord, most countries agreed to scale back greenhouse gas emissions. A few refused, arguing that poor countries would be blocked from growth if they were forced to reduce greenhouse gases.

Into this cauldron of opinions and interests—involving scientists, economists, activists, developing countries, and industrial powers—USAID has contributed expertise and served as a voice for what works in poor countries. USAID is helping countries prepare for climate change while seeking new ways to grow.

Developing countries are especially affected by changes in climate because their economies are vulnerable, they are less able to change, and climate variability was already a challenge to them, said Bill Breed, USAID’s top climate change specialist.

“The chemistry of the ocean is changing—it is becoming more acidic” from absorbing increased carbon dioxide in the atmosphere, Breed said. Acidic oceans disrupt food chains, which could reduce fish numbers.

There has been a change in precipitation patterns, he added—some places get more rain, others get less, and the timing and volume matter.

For example, in Kenya the seasonal rains that usually come like clockwork are becoming unpredictable. Droughts from 2003 to 2006 led to a 90 percent loss of livestock in some areas. As a result, nearly 11 million people required food aid.

“Such changes exacerbate existing development challenges,” said Breed. “In the tropics, they affect countries already operating at the margins.”

Children in southern Kazakhstan play near a water pump. USAID responded to water scarcity tensions in the country by increasing access to drinking water and irrigation.

The Agency provides information to help prepare for the effects of climate change such as rising seas, storm surges, droughts, and unpredictable rain patterns.

“We are making our projects and activities more resilient to climate change,” Breed said.

Some crops, for example, may no longer be able to get the rain they need, or the rain may fall during flowering periods, which reduces fertilization. So experts are helping farmers breed crops that can thrive in new conditions such as heat, drought, and flooding. They also show farmers how to harvest water by building small structures to catch and hold water.

“The question one asks is if a place is going to be habitable in 10 or 15 years,” said Breed. A community may require a change in crops or practices, or even that people move away to survive.

Breed suggested looking at Phoenix, Ariz., in the southwestern United States where the water table fell from 6 feet to 400 feet below the surface in some areas as aquifers were tapped to supply a growing population. In the U.S. case, ample power allows lifting of water to meet needs, but even here limits are increasingly apparent.

To help anticipate climate changes, USAID has set up geospatial observation centers with NASA and developing country institutions in Africa and Central America. The centers analyze satellite observations, historical data, local environmental information, and forecasts to help figure out how to adapt, manage the environment, and prepare for disasters.

The centers monitor changes in forests and land cover, greenhouse gas emissions, and red tides. They give advance warnings of thunderstorms, and identify places likely to be flooded.

The climate change experts also see an opportunity to “build settlements better” with improved drainage that can prevent flooding and water damage.

A farmer fetches corn from a mud silo at Janjori-Kukuo in Ghana. With USAID support, farmers in Ghana have improved their crop production as climate change puts additional stress on agricultural systems in Africa.

USAID also helps countries promote clean energy and make their utility sectors more profitable. Electricity is often subsidized in developing countries, which doesn’t make economic sense since it is typically the rich, with the highest rate of consumption, who reap the benefits.

“Over the next 50 years we need to cut emissions [of greenhouse gases] by 50 percent from current levels,” said Breed. “We need …clean technology. Although we need electricity, efficiency and conservation are part of the picture.”

USAID plans to help countries attract investment for clean development and enable their participation in carbon markets. The Agency is also working on pilot projects on carbon finance—paying people to reduce greenhouse gas emissions or increase carbon storage.

Protecting forests is a major factor in reducing climate change. In East Africa, USAID worked with 35,000 small-scale farmers to plant 4 million trees for carbon trapping, environmental benefits, and personal use. Farmers are paid for the carbon their trees take in and store.

U.S. funding for core international climate change efforts has grown from $316 million in 2009 to more than $1 billion in 2010 and reaches nearly $1.4 billion in the administration request for 2011. USAID, the State Department, and the Treasury Department use this money to meet the challenges that come with a changing climate.