Climate change refers to long term regional or global changes in average temperature, humidity, and rainfall (NASA 2016). Climate change estimates vary, but a National Academy of Sciences and Royal Society report indicates that earth’s average surface air temperature has “increased by about 0.8ºC (1.4ºF) since 1900” (National Academy of Sciences and The Royal Society, 2014). While some climate change occurs naturally, human-produced greenhouse gases, which trap heat in the earth’s atmosphere, are causing the bulk of this change. Leading scientists and policy makers agree that climate change is one of the greatest problems facing society due to the effects on agriculture, sea levels, and other environmental conditions.
Climate Change Causes, Characteristics, and Environmental and Policy Issues
Natural phenomena and human activities are causing climate change, with human activities having a dramatic impact since industrialization. Leading human causes of climate change are related to the burning of fuels and other pollutants:
Carbon dioxide, methane, nitrous oxide (N2O) and three groups of fluorinated gases (sulfur hexafluoride (SF6), hydrofluorocarbons (HFCs), and perfluorocarbons (PFCs)) are the major anthropogenic [human created] greenhouse gases. (Wikipedia contributors. 29 July 2016. “Greenhouse Gas.”)
Burning coal, natural gas, and petroleum for electricity and heat has been the primary cause of CO2. (Wikipedia contributors. 29 July 2016. “Greenhouse Gas.”) Figure 1 shows the rise in CO2 in parts per million of in the atmosphere over 1000 years:
(Source: The National Academy of Sciences; The Royal Society (2014) (Figure Atmospheric measurements (ML) Law Dome by Eric Wolff, data from Etheridge et al., 1996; MacFarling Meure et al., 2006.)) Note: Modern atmospheric measurements from Mauna Loa are superimposed in blue.
In terms of sea level rise, Climate Ready Boston reports that “The overall trend in relative sea level rise (RSLR) in Boston between 1921 and 2015 has been about 2.8 mm/yr (0.11 in/yr).” Going forward “a 2050 range of 19 cm to 45 cm (7.5 to 18 in) can be considered, but higher RSLR approaching 75 cm (30 in) is possible.” (Climate Ready Boston 2016, page 6)
Changing weather patterns, which influence agricultural production and can also cause famines, such as that in Syria, which can influence societal unrest. (Fischetti, 2015; Gleick 2014)
Scientific and public debates over climate change have been challenged by the difficulty in attributing events specifically to climate change. As the National Academy of Science indicates:
A definitive answer to the commonly asked question of whether climate change “caused” a particular event to occur cannot usually be provided in a deterministic sense because natural variability almost always plays a role. (NAP, 2016, page 10)
Nonetheless, the broader patterns are clearly showing a warming trend and related phenomenon including rising sea levels. Despite attribution challenges, climate change models have been validated by recent measurements. As John Abraham reported:
[M]odels have been within 3% of the measurements. In my mind, this agreement is the strongest vindication of the models ever found, and in fact, in our study we suggest that matches between climate models and ocean warming should be a major test of the models. (Abraham, 2016)
For people and organizations interested in estimating the influence of human activities on CO2 output there are a variety of resources including Count Down Your Carbon and Carbon Footprint and the EPA’s Carbon Footprint Calculator.
Summary and Conclusions:
Climate change is one of the most serious challenges facing the planet. Key threats include rising temperatures, which influences agricultural production and rising sea levels, which puts many global cities at risk.
While there are many reasons to be pessimistic about our ability to address climate change, former Vice President and climate change activist, Al Gore makes the case for optimism in addressing climate change:
We’re seeing a continuing sharp, exponential decline in the cost of renewable energy, energy efficiency, batteries and storage — and the spread of sustainable agriculture and forestry — giving nations around the world a historic opportunity to embrace a sustainable future, based on a low carbon, hyper-efficient economy. (Gore 2016)
In particular, many people point to energy efficiency as the lowest cost energy option and a great solution for reducing human influences on climate change:
With costs ranging from about 2 to 5 cents per kilowatthour (kWh), utilities have been able to deliver energy efficiency to their customers at a lower cost than actual electricity, which has supply costs ranging from 5 to 15 cents per kWh. (Barrett and Stickles 2016)
While clean technology, energy efficiency, and technological solutions such as carbon capture sequestration (CCS) might address the issue; other more critical climate change activists argue that a significant deindustrialization process, reducing consumption, living more simply, and developing the “slow” movement such as slow food, may be needed to address climate change. (Smith 2014; Klein 2014)
Abraham, John. 27 July 2016. “Climate models are accurately predicting ocean and global warming.” The Guardian.https://www.theguardian.com/environment/climate-consensus-97-per-cent/2016/jul/27/climate-models-are-accurately-predicting-ocean-and-global-warming
Barrett, James and Brian Stickles. July 2016. “Lending for Energy Efficiency Upgrades in Low- to Moderate-Income Communities: Bank of America’s Energy Efficiency Finance Program.”
Report Number F1601. http://aceee.org/research-report/f1601
Climate Ready Boston. 1 June 2016. “Climate Change and Sea Level Rise Projections for Boston : The Boston Research Advisory Group Report .” http://climateready.boston.gov/
Fischetti, Mark 2 March 2015. “Climate Change Hastened Syria’s Civil War: Human-induced Drying in Many Societies Can Push Tensions Over a Threshold that Provokes Violent Conflict.” Scientific American.http://www.scientificamerican.com/article/climate-change-hastened-the-syrian-war/
Gleick, Peter. 3 February 2014. “Water, Drought, Climate Change, and Conflict in Syria.” American Meteorological Society. http://religioner.no/wp-content/uploads/2015/08/religioner.no_wcas-d-13-00059.pdf
Gore, Al. 25 February 2016. “The Case for Optimism on Climate Change .”
Johnston, Ian. 18 July 2016. “Global warming set to cost the world economy £1.5 trillion by 2030 as it becomes too hot to work.” The Independent. http://www.independent.co.uk/environment/global-warming-climate-change-economic-effects-jobs-too-hot-to-work-india-china-a7143406.html
Klein, Naomi, 2014. This Changes Everything: Capitalism vs. the Climate. Simon & Schuster. New York.
McKibben, Bill. 19 July 2012. “Global Warming’s Terrifying New Math : Three simple numbers that add up to global catastrophe — and that make clear who the real enemy is .” Rolling Stone.http://www.rollingstone.com/politics/news/global-warmings-terrifying-new-math-20120719
NASA. 2016. “Global Climate Change. http://climate.nasa.gov/
National Academy of Sciences; The Royal Society. 2014. Climate Change: Evidence and Causes. 2014. National Academies Press. Washington D.C. http://www.nap.edu/catalog/18730/climate-change-evidence-and-causes
National Academy of Science. 2016. Attribution of Extreme Weather Events in the Context of Climate Change. National Academies Press. Washington D.C. http://www.nap.edu/catalog/21852/attribution-of-extreme-weather-events-in-the-context-of-climate-change
Smith, Richard. 12 November 2014. “Climate Crisis, the Deindustrialization Imperative and the Jobs vs. Environment Dilemma ” Truthout. http://www.truth-out.org/news/item/27226-climate-crisis-the-deindustrialization-imperative-and-the-jobs-vs-environment-dilemma
Wikipedia contributors. 29 July 2016. “Climate Change.” Wikipedia, The Free Encyclopedia.https://en.wikipedia.org/wiki/Climate_change.
Wikipedia contributors. 29 July 2016. “Greenhouse Gas.” Wikipedia, The Free Encyclopedia.https://en.wikipedia.org/wiki/Greenhouse_gas.