Fact or Fiction
Climate science is no longer a matter of opinion, despite a handful of deniers and anti-science politicians.
An overwhelming number of scientists and research institutions support the notion that human activities are causing climate change, and that the consequences of continuing down this path could be catastrophic to future generations. The amount of greenhouse gases has risen dramatically. Global temperature is rising, despite the earth being in a cyclical cooling period. Weather is getting more extreme. The basic science of the cause and effect are well understood. At this stage, the real question is what we are going to do about climate change.
If you are not sure how to respond to some climate change deniers, here are some sites that help set the story straight, along with a mobile app so you are always prepared.
- National Academy of Science
- U.N. Grid
- Intergovernmental Panel on Climate Change
- Yale Forum on Climate Change & The Media
- Climate Reality Project
- Skeptical Science
- Skepical Science Phone Application
- The New York Times: Global Warming & Climate Change Pages
- Scientific American: The Future of Climate Change
- Duke University Climate Change Policy Partnership
What Is The Current Evidence?
The temperature of the planet has already increased about 1.5°F since 1850.
Ice is melting worldwide, especially at the Earth's poles.
Sea level has risen faster over the last century.
Dramatic weather evens are occurring with increasing frequency, including floods, storms, droughts, fires, and heat waves.
Potential Consequences of Climate Change
Dramatic increases in rain and flooding in some regions, with ongoing increases in heat waves.
Decreased rain in many regions, including US southwest and reduced streamflow.
Beach erosion, millions more at risk of flooding, loss of wetlands.
Changes to Earth’s geography, making parts of Earth uninhabitable.
Decreased crop yield, increased need for irrigation.
Increased weather related deaths, spread of infectious diseases.
Destruction of species and habitats, species migration.
For 1° to 4° C Warming
5–10% less rainfall per degree in Mediterranean, SW North America, southern Africa dry seasons
5–10% more rainfall per degree in Alaska and other high latitude NH areas
3–10% more heavy rain per degree in most land areas
5–10% less streamflow per degree in some river basins, including the Arkansas and Rio Grande
5–15% reduced yield of US corn, African corn, and Indian wheat per degree.
15% and 25% reductions in Arctic sea ice area per degree, in the annual average and September (respectively)
For 1° to 2° C Warming
200–400% increase in area burned per degree in parts of western US
For 3° C
Loss of about 250,000 square km of wetlands and drylands
Many millions more people at risk of coastal flooding
About 9 out of 10 summer seasons expected to be warmer than all but 1 summer out of 20 in the last decades of the 20th century over nearly all land areas
For 4° C
About 9 out of10 summers warmer than the warmest ever experienced during the last decades of the 20th century over nearly all land areas.
For 5° C
Yield losses in most regions and potential doubling of global grain prices.
Some climate change deniers attribute recent trends to natural variability. Scientific evidence suggests otherwise.
There are global changes in climate over time, such as the ice-age when the Earth cooled considerably. Additionally, while climate represents the average weather in a place over many years, year-to-year and decade-to-decade fluctuations do occur. As an analogy, if you flip a coin ten times, you expect to get 5 heads and 5 tails, but that does not happen every time; however, over time you will average heads half the time.
The vast and overwhelming scientific consensus is that natural climate variability cannot explain the warming trend seen since the mid-1800s, while most of the warming can be attributed to human activities that release greenhouse gases into the atmosphere.
Are there uncertainties in climate science? Absolutely. As we any field of science, our knowledge and understanding grows as we do more research. However, recognizing that there are limits to our current knowledge and ability to forecast the future, does not negate current scientific consensus on climate change. More/Less info
There are many factors that can affect predictions of future climate change, including the sources and uses of energy in the future. There are also area that need more research, including:
- How human-caused changes interact with natural climate variability
- Certain Earth system processes, such as the carbon cycle, ice sheet dynamics, and cloud and aerosol processes, are not yet completely understood or fully represented in climate models
- Climate change impacts typically play out at regional scale, but processes at these scales are not as well represented by models as continental to global scale changes.
- The interaction of climate change with other global and regional environmental changes, including changes in land use, management of natural resources, and emissions of other pollutants.
- The vulnerability and adaptive capacity of human and natural systems, which can vary widely in space and time and generally are not as well understood as changes in the physical climate system.