Montana Climate Change
Frequently Asked Questions - Education
Q: What is the difference between weather and climate?
A: Weather is the set of conditions that exist over relatively short periods, usually hours or days. The conditions may be hot or cold, wet or dry, calm or stormy, etc. Weather includes events such as thunderstorms, blizzards, or persistent heat waves. A seasonal drought remains a weather event. Climate embraces averaged weather patterns over past or future time periods. Put another way, weather determines the clothes we wear to go outdoors. Climate determines the crops we plant, when we plant them, and when we harvest them.
Q: What constitutes “Climate Change”? When does a weather pattern become a change in climate?
A: Climate change is a term that includes any significant change in measures of climate, such as temperature, precipitation, even winds that lasts for several decades or longer. Climate change may result from natural factors, such as changes in the sun’s intensity and slow changes in the earth’s axis rotation and orbit around the sun. Other natural processes within the climate system include changes in ocean circulation. Human activities are now known to change atmospheric composition, principally the build-up of carbon dioxide and other gases. The burning of fossil fuels and changes to the land surface, such as deforestation and urbanization are major causes of the growth of these so-called “greenhouse gases.” These high levels of greenhouse gases correlate to measurable rises in global temperatures.
Q: Why is the term “climate change” used rather than “global warming”? Isn’t global warming the problem?
A: The terms are often used interchangeably. But according to the National Academy of Sciences (NAS), the phrase “climate change” is preferred because it helps convey that there are other changes in addition to rising temperatures. Climate change refers to any significant change in measures of climate (such as temperature, precipitation, or wind) lasting for an extended period (decades or longer). Global warming is an average increase in the temperature of the atmosphere near the Earth’s surface and in the troposphere. This can contribute to changes in global climate patterns. Both global warming and climate change can be caused by a variety of factors, both natural and human-induced.
Q: What are the six greenhouse gases?
A: Three of the major greenhouse gases are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), each of which is found in nature. In contrast, three of the greenhouse gases are only emitted through industrial sources: hydrofluorocarbons (HFC), perfluorocarbons (PFC), and sulphur hexafluoride (SF6). These are potent greenhouse gases and can persist in the atmosphere for many decades, but they do not occur in nature. For modeling and forecasting purposes, greenhouse gases other than carbon dioxide are converted into their CO2-equivalents.
Q: When will the climate change begin?
A: Many scientists believe it is already underway. The Earth has warmed 1.3°F over the past century, and it is projected by the Intergovernmental Panel on Climate Change (IPCC) to increase by an additional 3.2-7.2°F over this century. These increases may appear minor, but they are changes in the Earth’s global average temperature nonetheless. To put this in perspective, global temperatures during the last Ice Age (about 20,000 years ago) were “only” 9°F cooler than today. At the high-end of projected warming, human activities would change Earth’s climate by up to 7°F, but in the opposite direction.
Q: Will humans become extinct because of climate changes?
A: Montana climatologist Dr. Steve Running, who shared the Nobel Peace Prize with his colleagues on the Intergovernmental Panel on Climate Change (IPCC), was asked this question by a young student following one of his popular lectures. He answered: “No. Humans are extremely adaptable. Remember, humans survived Ice Ages.” Changes in climate may cause serious world-wide problems, however. People in low-lying areas may be displaced. And large-scale population shifts could occur as food producing areas dry out. Certain plants and animals could become extinct. The problem is serious and is worthy of a coordinated global effort.
Q: What is Biodiesel? What is Ethanol? How do they differ?
A: Ethanol is a clear, colorless, flammable liquid. Agricultural alcohol in Montana is produced as a fuel and is generally fermented and distilled from any of a variety of grains. Its production is essentially the same as that for distilled spirits such as whiskey. Work is under way to make ethanol from cellulose --- plant fibers such as straw or even wood. Ethanol is often blended with gasoline. Biodiesel is made from natural oils or sometimes from animal fats. Camelina, canola, mustard, soybean, or other crops are grown and the oil is extracted. The biodiesel is typically produced by a chemical reaction between this oil and an alcohol such as methanol, in the presence of a catalyst. This yields the fuel and a waxy byproduct called glycerin. The “B” in biodiesel blends designates the quantity of biodiesel (e.g., B-80 is 80 percent biodiesel and 20 percent conventional diesel).
Q: What is a Carbon sink?
A: Carbon sinks are natural processes that remove more carbon dioxide from the atmosphere than they release over a given period of time. Terrestrial carbon sinks include forest biomasses, rangeland, and certain agricultural acreages. The oceans are also carbon sinks.
Q: How do forests store carbon?
A: Forests are natural reservoirs of carbon storage. Trees remove carbon dioxide from the air during the photosynthetic process. Sunlight and carbon dioxide gas are converted into carbon, some of which is stored as fiber in tree trunks and branches, foliage, and roots. During the process, some carbon dioxide is released back into the atmosphere. But more carbon is absorbed by trees than is transpired. Worldwide, forests store an astounding quantity of carbon derived from the atmosphere. At maturity, about 50 percent of a tree’s dry weight is carbon. The overall biomass of a forest and its soils acts as a “carbon sink,” effectively sequestering, or storing carbon.
Q: Don’t we exhale carbon dioxide? All the world’s people exhaling carbon dioxide must contribute a great deal to global warming, right?
A: It is true that all living animals exhale carbon dioxide. Scientists studying the presence of carbon in the atmosphere discount the contribution for several reasons. The quantities of human exhaled CO2, while perhaps measurable, are part of the natural carbon exchange that occurs between living things and the environment. This type of carbon contribution is not measured because it is cycled relatively quickly. Similarly, a great deal of carbon is stored in the world’s grains and food supplies. This is not measured, either, because it is cycled over a fairly short period of time as the food is consumed and the carbon released. The greater carbon cycle cannot be accurately measured because it simply won’t hold still long enough to take its pulse. But carbon build-up in the atmosphere can be measured and carbon cycling is clearly evident. The natural carbon cycle simply cannot absorb the quantities of carbon dioxide that have been sent into the atmosphere over recent decades. So, human-exhaled CO2 is much less a concern than are the activities of those breathing humans: automobiles, industry, land-clearing, etc.
