What is Climate Change

Climate is how the atmosphere ‘behaves’ over relatively long time periods (versus weather which describes atmospheric conditions over a short time period). Climate change means changes in the long-term average of daily weather. (Source: Caribbean Community Climate Change Centre (CCCCC))

According to the Inter-governmental Panel on Climate Change (IPCC), climate change is a change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties, and that persists for an extended period, typically decades or longer. Climate change may be due to natural internal processes or external forcings, or to persistent anthropogenic changes in the composition of the atmosphere or in land use.

According to the United Nations Framework Convention on Climate Change (UNFCCC),  climate change is 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.

Climate change is a now widely accepted theory which proposes that due to alteration of the concentration of various select gases in the earth’s atmosphere (greenhouse gases), the average surface temperature of the planet is increasing at an unprecedented rate. This is occurring in a process known as the greenhouse effect. These temperature increases are causing many unpredictable changes in climate and weather patterns worldwide which have implications for a range of disasters affecting human populations.

Impacts of Climate Change

Experts generally agree that climate change will alter weather patterns and lead to, for example:

• loss of biodiversity (variety of animals and plants) and shifts in biome,
• sea level rise,
• changes in the frequency and intensity of storms,
• melting of glacial and polar ice caps.

According to the IPCC, the Caribbean region is projected to see an increase in temperature of between 0.94 to 4.18 degrees Celcius while rainfall is projected to undergo changes of  between -49.4 to 28.9% by 2069 (relative to the 1961-1990 period). Sea level is also expected to rise 15 to 95 cm by 2100. These changes are forecasted to expose the Caribbean islands to:

• more intense and frequent disasters or novel ones altogether
• increased coastal flooding and salt water intrusion into fresh water aquifers (a major issue in light of sea level rise).
• heat waves and drought, which have accompanying hazards such as forest fires, are predicted to become more commonplace
• higher rainfall in the wet season and more regular, powerful storms which can exasperate flooding concerns
• altered hurricane tracks so that islands such as Trinidad and Tobago, may be forced to cope more regularly with this natural disaster.

Risk Management

Two approaches can be used in conjunction to ease the anticipated impacts of climate change – mitigation and adaptation.

Mitigation involves instituting methods to reduce radiative forcing and thus the degree of global warming/climate change that is likely to occur:

• Reduce emissions of greenhouse gases, especially through curbing deforestation,
• Increase the use of alternative ‘clean’/renewable energy sources
• Improve the efficiency of production processes via the adoption of low carbon technology. 

Recent international conferences and agreements such as the Kyoto Protocol (1997) and the UN climate summits in Copenhagen, Denmark (2009) and Cancun, Mexico (2010) are geared to attaining firm commitments from countries to reduce carbon emissions via the engineering of innovative and collaborative initiatives.

Although mitigation against climate change is necessary to sustain life as we know it on planet earth, it is recognized by the IPCC that some degree of climate change is inevitable on account of greenhouse gas composition changes that have already taken place in the atmosphere. Hence it is also essential for populations to adapt in the face of climate change in order to alleviate and reduce vulnerability to the negative effects that are predicated to occur. For example, small island nations can:

• limit the extent of coastal development in light of sea level rise,
• construct coastal defence systems to protect communities.

The uncertainty surrounding what form climate change may take in particular regions makes adaptation challenging. However improvement in climate modeling is increasing the confidence with which we are making climate change predictions which augurs well for improving our ability to adapt.

References:

• IPCC (2007) 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, UK: Cambridge University Press.
• IPCC (2007) Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson (eds).  Cambridge, UK: Cambridge University Press.

Further Reading:

• The United Nations Environment Program (UNEP) Climate Change Website
• The International Strategy for Disaster Reduction (ISDR) - Disaster Risk and Climate Change Website
• The Intergovernmental Panel on Climate Change (IPCC) Website
• The United Nations Framework Convention on Climate Change (UNFCC) Website
• The Caribbean Community Climate Change Centre (CCCCC) Website