Climate Change for Beginners: Addressing the Uninformed (Part 2 of 4 )
Despite ample evidence supporting the occurrence of global climate change, the consequences and risks associated with this change are seldom the topic of dialogue in classrooms, amongst communities, or even between those determining the fate of scientific policy (ahem, presidential candidates). This incredibly relevant, world-altering topic thus remains poorly understood and seemingly irrelevant in day-to-day life.
Americans, nevertheless, stand firm on their position in the divisive battle over the existence of climate change – a topic so infrequently on our radar that we actually lack the knowledge required to take a educated stance (or make an informed decision). A Yale University climate change literacy assessment concluded that over 50% of the American public would receive an ‘F’ (an F !!!) for their climate literacy, while only 1% has knowledge equivalent to an ‘A.’
Ummm, does anyone else see this as a problem?
Climate change is a very real (and unnerving) force. The Earth’s climate has warmed by approximately 1.4 – 3.3 degrees Fahrenheit (0.6 – 0.74 degrees Celsius) over the last century1,2, and further temperature rise is expected to occur at a rate of 0.25 to 1 degrees Fahrenheit per decade (2.5 to 11.5 degrees this century)2. Per decade! And, the scary truth . . . as dire as warnings of the consequences of global climate change have been, scientists are worried that predictions may be underestimating the speed and severity of these impending changes.
So, why is it that public understanding and acceptance of this issue remains a challenge? Are we failing in our attempts at scientific communication and public dialogue?
Scientific Literacy: Back to the Basics
Within the scientific community, there is widespread agreement that the earth is warming and the climate is shifting2. But, for a moment, let’s just forget about the complexities of scientific research and go back to the basics of the science behind atmospheric (and subsequent global) warming.
Climate vs. weather3. Climate and weather are intertwined, with people often mistakenly linking weather directly to climatic change. Before making this connection, though, the differences between weather and climate should be made clear. Weather comprises the conditions that occur over a short period of time (minutes to months), while climate defines the behavior of the atmosphere over relatively long periods of time. Climate is usually presented in terms of averages and extremes over time, quantified across decades or even millennia. When talking about climatic change, we are talking about the changes in these long-term averages of daily weather (including precipitation and temperature).
So, how then does a change in weather provide evidence for a long-term change in climate? Climate change refers to any significant change in the measures of climate that lasts for an extended period of time. In other words, climate change incorporates major changes in temperature and precipitation patterns (among others) that occur over several (to many) decades. Decreased snowpack, earlier springs, longer growing seasons, shifts in the timing of the ‘rainy season’, higher summer temperatures, and higher winter temperatures are all examples of how we can ‘see’ or feel the effects of long-term shifts in weather patterns and changes in climate over time.
Connecting weather events to climatic change can be a bit trickier, though. Extreme weather events (such as hurricanes or floods) are usually driven by a complex set of interacting factors, and some range of variability is to be expected. Determining whether or not a single, extreme event is linked to climatic change is actually quite difficult2. Regardless, recent studies provide evidence that the frequency and magnitude of extreme events and natural disasters can be linked to our dramatically altered climate (IPCC, 2012; Moritz et al., 2012).
Greenhouse Gases & Their Effect 2. The sun provides energy and warmth (via radiation) for all living things. Greenhouse gases are any atmospheric gases (such as carbon dioxide) that absorb radiation (the sun’s energy). The greenhouse effect is the actual trapping of heat by these gases, which leads to an increase in temperatures near the Earth’s surface (Figure 2). This atmospheric effect is analogous to the trapping of heat by the glass walls of a greenhouse (Figure 1). This trapping of heat is what keeps our planet warm, and thus livable. An increase in greenhouse gases has, however, intensified this effect. Our current level of atmospheric carbon dioxide is 380 parts per million (ppm), a nearly 40% increase from our pre-industrial level of 280 ppm 2. Scientific research provides us with evidence supporting a warming climate, driven predominantly by these rising levels of atmospheric carbon dioxide.
And, although many factors contribute to the accumulation of atmospheric gases, humans are largely responsible for most of this increase and the subsequent warming of the last 50 years. The largest human-driven contributions come from the burning of fossil fuels, which releases carbon dioxide gas into the atmosphere (Figure 3).
Although there is ample evidence for a rapidly changing climate, let’s stick with the most obvious examples. Melting ice is both a visible and documented response to global warming:
- According to USGS researchers, the total land area of glaciers in Glacier National Park (Montana) has decreased by over one-third since 1850.
- Record low arctic sea ice levels were documented this year. At 3.41 million square kilometers (1.32 million square meters), this is the lowest seasonal minimum extent since satellite records began in 1979 (National Snow and Ice Data Center).
- Athabasca Glacier (Jasper National Park, Alberta) has been receding for the last 125 years, losing half of its mass and retreating more than 0.9 miles (1.5 kilometers) as a direct result of the warming climate.
Forget Environmental Impacts. Let’s focus on YOU.
As scientists, maybe we took a wrong turn somewhere when it came time to relay our knowledge to the public. Framing information makes all the difference in its understanding and acceptance. Messages and recommendations must relate to core values and locally relevant issues, lest they be lost in our already information-overloaded society.
So, instead of thinking about the detrimental affects of climate change on the environment (plants, animals, ecosystems – what we, as scientists, often focus on), let’s talk about how climatic change will impact you. Ignoring the environment altogether, climate change still poses a serious global risk – think more severe droughts, less snow and rain to recharge aquifers and reservoirs, an increase in catastrophic impacts from natural disasters, larger and more intense wildfires . . . you get the point.
Changes in climate impact everyone (yes, you included). Shifts in temperature and precipitation (whether up or down) directly affect the products YOU rely upon – most notably: forests, clean water, and crops. When forest trees are stressed or lost, our main source of clean air production is lost (trees remove carbon dioxide from the atmosphere in exchange for the oxygen we breathe). When snowpack diminishes and glaciers melt, drinking water supplies diminish. When extreme drought occurs, agricultural products and the national economy are directly impacted. As Bill noted in his biofuels post, 78% of the US corn supply experienced some level of drought in 2012, leading to a 12% cut in production. Such decreases directly impact food production, transport, and costs. You purchase food grown on a farm and transported to the grocery store, right? So, yes, this does impact you.
Beyond these seemingly more direct impacts, shifts in climate also lead to numerous indirect impacts that are driven by long-term changes in weather patterns, including:
|Increased Average Temperature||
So, now that you have the facts and the information to take an educated stance, are you convinced?
Is ignorance really bliss? Or (to use another cliche), is knowledge power? Does scientific literacy make a difference? Or, do your cultural or political beliefs trump scientific truth? Let’s see if Kristin and Mike can convince you otherwise.
Until then, I’ll leave you to ponder the reason behind the lack of climate change discussion on the campaign trail . . . Is silence really an effective strategy?
1Jones, P.D., Osborn, T.J. & Briffa, K.R. (2001). The evolution of climate over the last millennium. Science, 292, 662–667.
2 IPCC, 2007: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 996 pp.
3 NASA website. What’s the difference between climate and weather? http://www.nasa.gov/mission_pages/noaa-n/climate/climate_weather.html
4 Hansen, J., R. Ruedy, M. Sato, and K. Lo, 2010: Global surface temperature change. Rev. Geophys., 48, RG4004, doi:10.1029/2010RG000345.