Climate FAQ

Part 1 - Science

What exactly is “climate change?”

First, a word on the definition of climate. “Climate” refers to temperature, precipitation, and wind patterns that prevail over an extended period of time. Climate can refer to prevailing patterns at local, regional, and global scales. For example, Buffalo typically is snowy in the winter. The wind often blows hard in the Great Plains. Temperatures in the Northern Hemisphere are warmer in July than they are in January.

Human society depends on a stable climate. Since the end of the last Ice Age some 12 millennia ago, a stable, moderate climate has provided a necessary condition that allowed for the growth of modern civilization.

“Climate change” refers to persistent changes in climate patterns lasting for decades or longer. The changes can be the result of natural factors, human activities, or a combination of both. More about the causes of climate change below.

What are “greenhouse gases”?

“Greenhouse gases,” such as carbon dioxide (CO2), trap the sun’s energy close to the earth’s surface, preventing its re-radiation into space. Greenhouse gases are a natural component of the atmosphere. Without them, the earth would be much colder and inhospitable to life as we know it.

A very rapid increase in greenhouse gases over the past 250 years has been documented, however. In a research enterprise that has spanned four decades and included hundreds of specialists, scientists have documented that burning fossil fuels – coal, oil, and natural gas – for energy has increased the concentration of CO2 in the atmosphere. The atmosphere’s CO2 level has increased by more than one-third since the mid 18th century, when industrial society began relying heavily on fossil fuels for energy.

Use of fossil fuels also has resulted in emissions of other greenhouse gases, including methane and nitrous oxide. Changes to forests and grasslands that absorb CO2 and have played a role in keeping CO2 levels stable over long periods of time have allowed still more carbon dioxide to build up in the atmosphere.

The higher quantity of greenhouse gases in the atmosphere is trapping additional heat and is linked to a rise in global average temperatures.

What’s the difference between “climate change” and “global warming?”

While the terms “climate change” and “global warming” often are used interchangeably, scientists prefer the term “climate change” to describe the impacts of emitting greenhouse gases. A documented increase in global average temperatures – “global warming” – is one consequence of those emissions. There are other consequences as well, such as changes in precipitation patterns, that will be described in more detail in Part II.

Is the climate really changing?

Yes. Temperature records show that there is a long-term trend of rising global average temperatures, which have increased by about 1.3 degrees Fahrenheit over the past century. That may not sound like much, but in the context of a global average, it is highly significant. Other signs of a changing climate include rising sea levels, shrinkage of the Arctic ice cap, warming of ocean waters, and increased frequency of drought in the tropics.

In thinking about recent climate change, it’s important to remember that scientists are referring to a long-term trend that is global in scale. Local weather patterns are not suitable gauges for determining whether and how the global climate is changing. By themselves, unusual weather events neither prove nor disprove the reality of global climate change. For example, a heat wave in a normally cool region is not proof of a changing climate, nor are unusual cold or heavy winter snowfalls proof that the climate is not changing.

Natural climate variability will continue to occur. Natural variability, such as recurring El Nino and La Nina episodes, could mask or amplify the long-term warming trend linked to human-caused greenhouse gas emissions. Short-term temperature variations should not be used to draw conclusions about the long-term temperature trend.

How do scientists know that climate change isn’t the result of natural causes?

The documented increase in the atmosphere’s carbon dioxide levels over the past 250 years is very unusual. Since 1750, CO2 levels have increased far outside the range in which they fluctuated during the past 650,000 years, as documented from ice samples extracted from deep inside large ice caps. The ice samples serve as a time capsule because they contain bubbles of ancient air that can be analyzed for CO2 content. Ratios of air molecules in those bubbles can be used to discern long-ago air temperatures. In addition, the rate of CO2 increase is highly unusual given what’s occurred before. Reconstructions of past climate conditions using proxy temperature data and computer models show that the second half of the 20th century likely was the warmest 50-year period in the past 1,300 years.

The recent increase in CO2 has been attributed to burning fossil fuels, because carbon contained in these fuels has a chemical signature that differs from carbon that originates from inorganic sources, such as volcanic eruptions.

Scientists have examined the possible role of natural causes in accounting for recent global climate change. For example, there has been a small increase in energy output from the sun during the industrial era, but it is well below the level that would be required to explain all of the documented increase in global average temperatures.

In addition, the pattern of warming, such as warming of the atmosphere’s lower levels and cooling at higher levels, is inconsistent with warming patterns that would occur if natural factors were the cause.

I’ve heard that climate scientists rely on computer models for climate research. How reliable are these models?

Climate models sometimes are derided as little more than guesswork, but such criticisms are off base. Climate models are mathematical representations of climate that are based on the laws of physics. Models are continually subject to vetting and validation. Models have been tested by comparing their simulations of current climate change with actual observations, such as the faster increase in nighttime temperatures compared to daytime temperatures that has taken place.

Modeling is not the only way that climate scientists go about their work. Scientists carry out extensive field research around the world, collecting data from the atmosphere, oceans, ice caps, and ecosystems. This work expands knowledge about climate phenomena and improves understanding of the many ways that climate change will affect the natural world and human society.

How can climate scientists project what the climate might be like decades from now when it’s impossible to predict the weather for more than a week out?

Weather forecasting and climate projections are very different. For predicting weather, meteorologists must consider many variables that come into play and can change rapidly. With the complex interplay of variables, small differences in initial conditions can lead to widely different outcomes that cannot be predicted more than a week or so out. That’s why no weather forecaster could make a credible prediction of what the high temperature in a given city will be six months from now.

Over long periods of time, however, the many variables that affect weather tend to smooth out and long-term trends can be discerned. Such trends can be used to make reliable projections about what the weather is likely to be in a given locale months in advance. You could plan an outdoor picnic in San Diego for the next Fourth of July with confidence that the day is likely to be warm and dry. You also know that if you decide to hold that outdoor picnic in Seattle on New Year’s Day, the event is likely to be spoiled by cold and rain.

Over the long term, climatologists can calculate the impact of atmospheric greenhouse gas levels and make credible projections on how those levels are likely to affect climate decades from now.

What are climate scientists projecting for the future?

The 2007 assessment released by the Intergovernmental Panel on Climate Change (IPCC), a global climate research enterprise comprised of leading climate scientists from around the world, published six scenarios projecting likely global average temperature increases during the remainder of the 21st century. The best estimates for the scenarios project a temperature increase ranging from 3 to 7 degrees Fahrenheit – far more warming than we saw in the 20th century.

You can download and read IPCC reports. For lay readers, the Summary for Policymakers provides a good overview of climate change science, impacts, and solutions.

Part II – Impacts

What are the likely impacts of climate change going forward?

At first glance, it may be easy to think that a warming atmosphere means only that our world will get a little warmer. In fact, the impacts of a warming atmosphere are likely to be numerous and serious. They include:

•   Warmer and more frequent hot days and nights

•   Increased frequency of extreme weather, including heat waves and intense rainfall events

•   Increase in areas affected by drought

•   Higher frequency of intense tropical cyclones

•   Higher sea levels

Why do these impacts matter to human society?

Hotter temperatures are likely to shrink snow and ice cover, which has ramifications for areas that depend on glaciers and mountain snowpack for water supplies. Those areas include much of the Western U.S. and heavily populated parts of Asia that depend on Himalayan glaciers to supply water for drinking, crop irrigation, and hydroelectric power generation.

More people die as a result of heat waves than any other form of extreme weather. Increasing frequency and intensity of heat waves will increase the risk of heat-caused mortality in vulnerable populations, such as the elderly, chronically ill, and socially isolated.

Increased frequency of drought has ramifications for food production, water supply, and hydroelectric power generation.

Higher frequency of intense tropical cyclones and rising sea levels would result in more coastal flooding episodes. In poor, low-lying countries many people would be displaced.

U.S. military planners are concerned that climate change could lead to natural and humanitarian disasters on a much larger scale than we’ve seen before. The result would be political instability that is a breeding ground for terrorism and violent unrest.

A panel of retired generals and admirals, including a former Army Chief of Staff and a former Vice Chief of Naval Operations, released a report in 2007 concluding that climate change is a “threat multiplier for instability in some of the most volatile regions of the world.” You can download and read their report.

What do scientists mean by “abrupt climate change?”

Evidence from the distant past shows that climate can change rapidly to different conditions in periods as short as a decade. The concern is that adding greenhouse gases to the atmosphere could perturb the climate system to a point at which it shifts rapidly, leading to consequences that would be difficult for human social and governance systems to cope with.

What, specifically, could happen in the United States as a result of climate change?

In 2009, the federal government released a report describing projected impacts of climate change in the U.S. In general, the report said that warming in the U.S. over the past century has been comparable to the rise in global average temperatures over the same time period. Observed evidence of climate change in the U.S. includes greater frequency and intensity of downpours and reduced snow cover.

Other conclusions in the federal report:

•   Flood and water quality problems are likely to be amplified in many regions.

•   Higher temperatures will challenge farming. Projected stresses include lower crop yields, water shortages, and growth in pest populations.

•   Coastal areas, especially on the Atlantic and Gulf coasts, are at risk from rising sea levels and storm surges.

•   Health impacts tied to hotter temperatures include greater heat stress for vulnerable populations, poorer air quality, and diseases transmitted by rising rodent and insect populations.

Projected regional impacts vary. For example:

In the Northeast, there will a higher frequency of days over 90 degrees, resulting in greater frequency of heat waves and greater potential for formation of harmful ozone air pollution, which is caused by the reaction of air pollutants in the presence of strong sunlight. A hotter climate will make northern New England’s climate in the 2070s more like today’s climate in the Carolinas. Production of popular berry crops and of maple syrup are likely to decline. Loss of snow cover will harm the winter recreation industry.

In the Midwest, there will be significant reduction in Great Lakes water levels as a result of higher evaporation rates, causing adverse impacts on shipping, beaches, and lakeside ecosystems. Elsewhere in the Midwest, intense precipitation events in the winter and spring will result in increased flood danger for communities alongside streams and rivers, and increased risk of waterborne disease outbreaks. Higher temperatures will extend the crop-growing season, but negative impacts will include more favorable conditions for plant pathogens, weeds, and pests.

In the Southeast, the number of very hot days in an already warm, humid region is projected to rise at a greater rate than average temperature, resulting in greater risk of heat stress for people, farm animals, and fisheries. More frequent droughts could occur in the Gulf Coast states as a result of soil moisture and water loss caused by higher evaporation rates. Rising sea levels will result in accelerated coastal erosion and flooding. Rising sea levels and greater coastal erosion will make coastal communities more vulnerable to storm surges.

In the West, warming temperatures will result in reduced snowpack, a natural form of water storage, leading to reduced summer water flows and reduced availability of water for summer irrigation and hydroelectric power generation. Projections point to an increasing probability of droughts. An increase in wildfires linked to higher temperatures and more frequent drought will damage forests and harm the forest products industry. Hotter water temperatures will stress salmon and other coldwater fisheries. Hotter air temperatures will be detrimental for growing specialty fruit crops.

You can download and read the federal report.

Part III – Response

What must be done to head off the projected impacts of climate change?

Greenhouse gas emissions must be capped and reduced. Further delays in acting would subject the United States to unacceptable risks. A joint statement published in 2009 by the national science academies of the United States and 12 other large nations stated, “The need for urgent action to address climate change is now indisputable.” (Click here to download and read the full statement.)

The most important step that must be taken is to put a price on carbon dioxide emissions, through a statutory limit, a carbon tax, or a mix of those alternatives. Putting a price on carbon would signal energy markets that there is a cost to disposing of greenhouse gases in the atmosphere, and provide an incentive to diversify our energy choices away from excessive dependence on fossil fuels.

Low-carbon alternatives to fossil fuels include greater energy efficiency, renewable energy sources, and nuclear power. Expanding use of low-carbon energy technologies will have important additional benefits - achieving greater energy security through reduced dependence on oil and creating opportunities to build new industries and jobs developing cleaner energy technologies.

Why should the U.S. limit emissions when other large countries, such as China and India, refuse to limit their emissions?

The U.S. cannot fight climate change alone, but without U.S. action, there is little chance that other countries will reduce their emissions. U.S. political, diplomatic, and technological leadership is indispensable for crafting international agreements to limit emissions and to expanding the use of advanced technologies that will supply the energy that growing economies need without causing unacceptable climate risks.

The U.S. is the most powerful country in the world and will remain so, as long as we face up to major challenges and take steps to deal with them. Deferring to other countries would be a sign of weakness.

Why don’t we just adapt to whatever climate changes occur?

There is evidence that the climate already has begun to change, so a degree of adaptation will have to be carried out, even if ambitious measures are taken to reduce greenhouse gas emissions. Planning should begin now to secure adequate water supplies and ensure the resiliency of important civil infrastructure.

Adaptation alone, however, would be very risky. If nothing is done to limit greenhouse gas emissions, the best evidence tells us that climate change is likely to worsen, exposing our economy, public health, and environment to risks of very serious harm.

A tenet of conservatism is to anticipate risks and take prudent measures to reduce them. Ignoring risks and refusing to reduce them is both selfish and irresponsible. Future generations will depend on a stable climate. Doing nothing to fight climate change would impair our descendants’ freedom to make their own choices and build prosperous, fulfilling lives. It would breach the contract among generations that Edmund Burke, the founder of modern conservatism, taught us is fundamental to maintaining a healthy society.

Are there technological fixes that would prevent climate change and allow us to stick with our current energy system?

A number of scientists are researching “geo-engineering” approaches to limiting the impacts of the greenhouse gas buildup in the atmosphere. Among the ideas that have been raised are fertilizing the ocean to encourage the growth of carbon-consuming plankton, and spraying tiny particles high in the atmosphere to reflect sunlight back to space.

While geo-engineering research is worthwhile, such projects should not be viewed as a panacea. There is not enough information at this time to determine whether they would be feasible or affordable, nor has enough research being carried out to understand potentially harmful consequences of implementing them.

What is cap-and-trade?

Cap-and-trade refers to a market-oriented method of addressing pollution that caps emissions and distributes emissions allowances under that cap. Allowances can be bought and sold. Emission sources that emit more than their allowed limit would have to buy more allowances. Emission sources that cut their emissions below their limit would accumulate surplus allowances, which they could sell. Consequently, a market in salable allowances would encourage emission sources to adopt cost-effective energy efficiency and low-carbon energy technologies that reduce emissions.

This method of reducing pollution has a conservative lineage that would surprise detractors who have demagogued it as a “cap and tax” scheme. The origins of cap-and-trade actually can be traced back to the Reagan White House. C. Boyden Gray, while serving as counsel for Vice President George H.W. Bush, embraced the idea of emissions allowances trading as a market-friendly alternative to the “command and control” pollution reduction approach typically favored by bureaucrats.

In 1990, the first Bush Administration pushed cap-and-trade as a novel way to reduce the sulfur dioxide emissions responsible for acid rain. The plan was part of the Clean Air Act amendments that passed Congress that year and were signed into law by President Bush. Cap-and-trade was a great success, reducing sulfur dioxide emissions faster and at a much lower cost than had been anticipated.

Why did REP support the House energy bill when so many Republican leaders opposed it?

The American Clean Energy and Security Act (ACES) is not the bill that REP would have written. It is overly complex and prescriptive. Nevertheless, House approval of the bill was a useful step forward, because further delay in dealing with climate change is not acceptable. It was the only vehicle in the House for dealing with the issue.

Had House Republican leaders offered a responsible, credible alternative to ACES, REP would have championed it and encouraged Congress to support it. Unfortunately, our party’s House leaders chose to play politics with the issue, sending a message that partisan politics is more important to them than dealing responsibly with our country’s problems.

Now that the arena for climate legislation has moved to the Senate, we encourage both parties to tone down the rhetoric and work together responsibly to improve the legislation and broaden public support for it. We are pleased with the leadership that Senator Lindsey Graham (R-SC) has shown in working with Senators John Kerry (D-MA) and Joseph Lieberman (I-CT) to craft legislation that can garner broad support.

What would ideal climate legislation look like?

REP prefers legislation that would put a price on carbon dioxide emissions, through a statutory limit, a carbon tax, or a mix of those alternatives. We support returning nearly all revenues raised by allowances sales or a carbon tax to citizens..

A variation of cap-and-trade has been dubbed “cap-and-dividend,” CO2 would be capped. Power plants, refineries and other CO2 sources would be required to obtain allowances in auctions, and the bulk of revenues given to citizens through offsetting tax reductions or dividend checks.

Alternatively, CO2 emissions could be taxed to encourage cutbacks in emissions. Proceeds of the tax should be returned to citizens. The tax rate could be adjusted periodically to ensure that CO2 reductions necessary to stabilize the climate actually are achieved.

In addition, REP favors measures to promote energy efficiency and to diversify America’s energy portfolio through expansion of renewable and nuclear energy. Promoting greater efficiency and developing more energy choices will cut consumer energy bills, reduce our exposure to volatile fossil fuel prices, cut the flow of dollars to unfriendly oil-exporting regimes, and develop new jobs at home producing cleaner energy technologies.

Additional information on REP’s positions on energy and climate issues is available by viewing REP’s energy and climate policy paper, on line by clicking here.

If Ronald Reagan were president today, what would Reagan do?

History tells us that he would support a responsible effort to reduce greenhouse gas emissions and keep the climate stable. In the mid-1980s, scientists produced evidence that long-lived chemicals used in refrigeration equipment were leaking into the atmosphere and depleting the high-altitude ozone layer that protects us from the sun’s harmful ultraviolet radiation.

The politics of the issue were similar to those surrounding climate change today. Skeptics demanded more research. Some politicians and business leaders worried that developing substitutes for the chemicals would be prohibitively costly and that jobs would be lost if the chemicals were phased out. A few extremists insisted that the problem was a hoax.

Reagan weighed all of the information and decided that protective measures were called for. He dismissed skeptics and sided with his administration’s scientists and diplomats. He ordered the State Department to negotiate a strong but balanced treaty phasing out the chemicals. After the treaty was completed and ratified, President Reagan called it a “monumental achievement.”

Reagan took a conservative approach by supporting prudent protections in the interest of good stewardship. He saw that strong U.S. leadership informed by good science could deliver effective protections that successfully balanced environmental and economic considerations.

The results from the treaty show that Reagan was right. Emissions have fallen, the ozone layer is beginning to repair itself, and businesses made money developing viable substitutes for ozone-depleting chemicals.

Reagan’s approach was the right one. It’s one that his political successors should follow in responsibly addressing climate change.