Page 375 - Geosystems An Introduction to Physical Geography 4th Canadian Edition

Chapter 11 Climate Change 339
the Kyoto Protocol target projected net savings ranging from USD $7 billion to $34 billion a year. For Europe, scientists determined that carbon emissions could be re- duced to less than half the 1990 level by 2030, at no cost to society.
A comprehensive economic analysis prepared by economist Nicholas Stern for the British government in 2007 (The Economics of Climate Change, The Stern Review, Cambridge University Press, 2007) reached sev- eral conclusions concerning action on climate change. Foremost was that the worst impacts of climate change can be avoided if we take strong action now; delaying action is a dangerous and more costly alternative. Stern stressed the need for action on a global level, an inter- national response across both wealthy and poor coun- tries, and that a range of options already exists to cut emissions.
Mitigating Climate Change:
What Can You Do?
On an individual level, what can you do to address cli- mate change? The principal way to slow the pace of cli- mate change—not only as individuals, but also as an international community—is to reduce carbon emissions, especially the burning of fossil fuels. One way to begin this process is to examine the sustainability of your daily practices and take action to reduce your carbon footprint (review the discussion of an individual’s “footprint,” whether an ecological footprint, carbon footprint, or life- style footprint, in Chapter 1). One goal, discussed in Criti- cal Thinking 8.1, is to reduce atmospheric concentrations of CO2 to 350 ppm. Consider these ideas and statistics:
• Driving a vehicle that gets 30 miles per gallon saves 2.9 tons of CO annually over one that gets 20 miles per gallon. 2
• Replacing incandescent light bulbs with compact fluo- rescent (CFL) bulbs saves 100 pounds of carbon over the life of each bulb. Using LED bulbs more than dou- bles this savings.
• Eating less meat reduces demand for animal products; having fewer animals in feedlots reduces atmospheric methane emissions.
• Buying local produce reduces the use of fossil fuels for the transport of goods to supermarkets.
• Planting trees, especially native species, removes CO2 from the atmosphere; a typical temperate-region tree can store 700 to 7000 pounds of carbon over its lifetime.
All of your actions and decisions have positive and negative consequences for Earth’s environment and for our changing climate. Remember that actions taken on an individual level by millions of people can be effec- tive in slowing climate change for present and future generations. On a collective level, human society must strive to mitigate and adapt to climate change. For ex- ample, developers and land managers can change land- use practices to preserve forests and other vegetation.
Farmers can use methods that retain more carbon in the soil and plant crop varieties bred to withstand heat, drought, or flood inundation. In coastal areas, land- owners can utilize natural shoreline protection, such as sand dunes, and allow for shifting of natural features during storms. Coastal developers must embrace zoning restrictions that account for rising sea level. All societies can promote efficient water use, especially in areas prone to drought. These are only a few examples among many for mitigating and adapting to climate change (for links and more information, see www.unep.org/climatechange/ mitigation/ and climate.nasa.gov/solutions).
Both governments and businesses are now planning for climate change impacts. For example, in New York City—in response to the damage from Hurricane Sandy in 2012—over $1 billion is being spent on upgrades to raise flood walls, bury equipment, and assess other changes needed to prevent future damage from extreme weather events. The potential for water scarcity and food shortages in hotter climates with more frequent droughts is emerging as a critical issue for the global community. However, unless greenhouse gas emissions are curbed substantially, the effects of climate change on Earth systems could outpace efforts to adapt.
Present greenhouse gas concentrations will remain in the atmosphere for many decades to come, but the time for action is now. Scientists describe 450 ppm as a possible climatic threshold at which Earth systems would transition into a chaotic mode; with accelerating CO2 emissions, this threshold could occur in the decade of the 2020s. The goal of avoiding this threshold is a practical start to slowing the rate of change and delaying the worst consequences of our current path. The infor- mation presented in this chapter is offered in the hope of providing motivation and empowerment—personally, locally, regionally, nationally, and globally.
CrITICALthinking 11.3
Consider Your Carbon Footprint
in Chapter 1, Critical Thinking 1.1 on page 11, you as- sessed your “footprint” in terms of your impact on earth systems. (See an example of a carbon footprint calculator at coolclimate.berkeley.edu/carboncalculator.) now, in the context of climate change mitigation, consider how the questions asked in a carbon footprint assessment—for example, what type of lighting, heating or air condition- ing, and transportation you use—represent your personal contribution to CO2 emissions. in other words, given what you now know about atmospheric greenhouse gases and energy budgets, how does your personal energy use and food consumption relate to climate change? next, expand your footprint assessment to your campus: is an en- ergy audit available for your campus? is a carbon-footprint reduction program in place? is your college or university cooperating with national efforts to conserve energy and recycle materials, saving money and reducing CO2 emis- sions? Do some research to answer these questions, and then get involved in some campus initiatives to promote resource conservation and sustainable lifestyles. •