2.2 Definition of Terms
2.2.1 Climate Change
Generally, climate change has generated much attention in recent times that many studies take a clear definition of the term for granted. Most studies adopt conceptual models presented in a wide array of technical reports (see IPCC, 2001, 2007; NOAA, 2007; UN- ISDR, 2008; World Nuclear Association, 2014). The Intergovernmental Panel on Climate Change (IPCC) defines climate change as “any change in climate over time, whether due to natural variability, or as a result of human activity” (IPCC, 2007: 21). Put differently, it refers to “observable changes (e.g. using statistical tests) seen in the mean values or properties of the climate, persisting over an extended period of time (a decade or longer) whether caused by natural variability or anthropogenic effects”.23
While the IPCC definition attributes causality to both natural and anthropogenic agencies, the United Nations Framework Convention on Climate Change (UNFCCC) emphasized anthropogenic causality, in defining climate change as “a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere, and which is in addition to natural climate variability, observed over comparable time periods” (UNFCCC, 1992: 7). Building upon the anthropogenic focus of the UNFCCC conceptual model, the United Nations International Strategy for Disaster Reduction (UN- ISDR, 2008) defines the phenomenon as the alteration of the world’s climate system which results from human activities including, but not limited to the burning of fossil fuel and the
23 IPCC, Working Group II (2007) “Glossary of Terms”, IPCC Fourth Assessment Report: Climate Change 2007,
Working Group II: Impacts, Adaptation and Vulnerability.
http://www.ipcc.ch/publications_and_data/ar4/wg2/en/annexessglossary-a-d.html
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clearing of forests thereby causing an increase in atmospheric concentration of greenhouse gas (GHG).24
Some conceptual models highlight technical assessment standards. For example, the National Climate Data Centre (2007) defines climate change as a long term shift in the statistics of weather, including changes in measurable average values such as normal or expected temperature, or precipitation, in a particular place and time, across decadal frame. In the same vein, the United States Climate Change Information Resource centre (CCIR-NYC) describes global climate change as an indication of changes in either the mean measure of the climate or in its variability which persists for several decades or longer, including changes in average weather conditions on earth indicated in such averages as global temperature, regional frequency of heat wave experiences, the occurrence of droughts, floods, storms, and other extreme weather events (CCIR-NYC, 2005).
The World Nuclear Association (2014) attempts a quantitative assessment of climate change, highlighting changes in the composition of greenhouse gases in the lower atmosphere particularly, the steady increase of CO2 levels to about 400 ppm.25 The NOAA’s Earth System Research Laboratory Global Monitoring Division (NOAA, 2015) puts this contextually in noting that from its May 2013 meteorological reading, daily mean concentration of carbon dioxide in the atmosphere of Mauna Loa, Hawaii26 surpassed 400 ppm for the first time since data capture began in 1958.27 Definitions in scholarly research have also borrowed, built upon, or adopted definitions from these technical reports. Hegerl et al. (2007) describe climate change as variations in the mean state of climate on temporal and spatial scales beyond those of individual weather events such as extended drought, floods and conditions that may result from El Nino and La Nina events.
A number of reports show evidence of long term climatic changes for specific locations monitored over time (see IPCC, 2001; Oechel et al., 1993; Parmesan and Galbraith, 2004).
24 Greenhouse gases (GHGs) “are those gaseous constituents of the atmosphere, both natural and anthropogenic, that absorb and emit radiation at specific wavelengths within the spectrum of thermal infrared radiation emitted by the Earth’s surface, the atmosphere itself, and by clouds.” The primary greenhouse gases include H2O, CO2, N2O, CH4 and O3. IPCC Fourth Assessment Report, Working Group I, Glossary of Terms:
http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Annexes.pdf
25 PPM stands for ‘parts per million’.
26 Mauna Lao in Hawaii serves as a primary global benchmark site for meteorological data capture.
27 The May 2013 reading marked a one-third increase in the last 200 years. Half the increase was recorded in the last 30 years, with ice core samples showing higher levels of carbon dioxide and methane than at any time in the past 650,000 years.
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Parmesan and Galbraith (2004: 3) for example, observe that “the United States has warmed during the 20th century by 0.8°C overall, with the greatest increases in temperature occurring at higher latitudes in line with predictions from climate models in use by sources including the IPCC.” In parts of Alaska, it is recorded that average annual temperatures have increased by 2-4°C (4-7°F) since 1900—a much higher increase than occurred in most contiguous areas in the United States (Oechel et al., 1993; IPCC, 2001; Parmesan and Galbraith, 2004).
Figure 1: Meteorological temperature data of annual mean and a five year mean indicating anomalies 1880-2010
Source: NASA (2015).
On a global scale, Toulmin (2009) highlights some evidences of climate change and points out that there has been an increase in the concentration of atmospheric CO2 from a pre- industrial value of about 280 ppm in 1750 to 379 in 2005, as compared to a 20 ppm increase in about 8,000 years before the industrial revolution. While the current CO2 levels stand at 430 ppm, there is the likelihood of it reaching a 550 level by 2035 with a 77-99 per cent possibility of global temperature exceeding 2oC. Similarly, In its 2001 report—The Science of Climate Change, the Intergovernmental Panel on Climate Change (IPCC) corroborating earlier linkages between increases in the level of greenhouse gasses and global warming, notes that temperatures have risen by about 0.6°C (1.1°F) globally. The IPCC further notes that sea level rise has been occurring globally since the end of the last glaciations with the
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current rate still projected to accelerate globally at the rate of 8-88 cm (3-35 in) by 2100 (IPCC, 2001. n. p).
Based on these observations and new scientific readings of the climate system, predictions have also been made on its future dynamics. The IPCC 2001 report noted that global temperature could witness an increase of between 1.4 and 5.8°C (2.5-10.4°F) over the next century (IPCC, 2001). Evans (2012, 3-8) similarly predicted that climate change will result in temperature increases of 1.1-3.1°C by the year 2060, and the changes will impact social and environmental systems through hazards such as excessive heat and the melting of glaciers which will result in secondary impacts including desertification, coastal flooding, land degradation, reduced crop yield, low water availability and food insecurity among others.