Environmental Issues

It is evident that humanity always experiences an array of lasting political and social problems that are evidently described in a famous monologue by Carl Sagan in his book Pale Blue Dot.  Being one of the greatest contemporary astronomers and astrochemists, Carl Sagan was clearly aware that there are more fundamental dilemmas and challenges of tremendous magnitute our civilization has to face.  One of these dilemmas is climate change, a global problem with serious implications for human existance.  Human consumption of fossil fuels has produced concentrations of greenhouse gases in the atmosphere that trap heat on earth, creating a gradual increase in average temperatures around the globe (IPCC, 2007).  Scientists predict that these warming temperatures will create both mild and severe changes in longstanding climate patterns that for millennia have driven human settlement, agriculture, and lifestyles (IPCC, 2007).

Climate change accompanied with higher temperatures will increase the rate of melting in the polar ice caps, which will result in rise of sea levels and gradually low-lying coastal territories like India, Bangladesh and many other will be in danger of permanent flooding.  The consequences of climate change range from millions of people appearing under threat of displacement and subsequent mass migration to humanitarian crises because of immense pressure put on agricultural production and food security.  The Intergovernmental Panel on Climate Change (IPCC) (2007) emphasized the importance of this of problem, indicating that climate change interacts at all scales, as well as with other global environmental and human forces, generating new and sometimes compounding impacts that have enormous and pervasive human consequences.  This particular paper aims to discuss and critically analyze the central aspects of the problematics of climate change, greenhouse effect, and global warming as well as their particular influence on agriculture.

LITERATURE REVIEW
In scientific literature, global climate change refers to continuing changes in global climate over long time, whether due to natural variability or human activity (IPCC, 2007).  The most recent report from IPCC unequivocally stated that global warming is occurring, human actions are behind the 0.8C rise in global average temperature since the industrial revolution, and if mitigation steps are not taken immediately there will be significant consequences for much of the world (IPCC, 2007).  Anticipating a doubling of preindustrial greenhouse effect, most climate models show mean global temperatures rising by 2-5 degrees Celsius from 2030-2060 (Stern, 2007, p.2).

Greenhouse effect is a complex natural process.  The sunlight that arrives to earth is reflected back in to the space, but the rest reaches the surface, warming the land, atmosphere and oceans (Lecture Notes, 2009).  The earth re-emits this energy in the form of infrared radiation (Lecture Notes, 2009).  However, greenhouse gases such as carbon dioxide, ozone, methane, etc trap this radiation and prevent its escape, thus causing increases in temperature (IPCC, 2007).  Literature indicates that carbon dioxide (CO2) is responsible for over 70 of the greenhouse effect (Hansen et al., 2008).  The result of the greenhouse effect is a warming of the earth surface.  Without these greenhouse gases its surface would be up to 30 degrees C cooler (Stern, 2007).  Human contribute to greenhouse gas concentrations and thus global warming through manufacturing, power generation, transportation, and livestock farming (IPCC, 2007).  The burning of coal, oil and natural gas is the key human factor in increasing greenhouse emissions because these fossil fuels used at a much faster rate than they were created (Stern, 2007).  The effects from global warming will vary sharply based on locality.  According to scientific opinion, those in the weakest economic andor developmental position are often the most vulnerable and thus the most susceptible to climate-related damages (Stern, 2007, p.vii).  Climate change leads to multiple biophysical changes from sea level increase and deglaciation to biodiversity loss and species extinction.  From the global perspective, climate change alters main agricultural patterns and impacts the ability of people to produce food.

ANALYSIS
In contemporary context, there is a growing concent in scientific literature and research on the potential biosocial changes climate change brings to global agriculture and food supply.  For instance, Rosenzweig et al (1993) explains that the effects of climate on agriculture in individual countries cannot be considered in isolation, because international agricultural trade provides constant flow of national food supplies to major importing nations and substantial income for major exporting nations.  Indeed, the world has performed well in terms of increasing food security, with food production outpacing population growth due to crop improvement, alteration of agricultural practices and development of infrastructures (Gillard, 2002).  However, Rosenzweig et al (1993) still express concern indicating close relationship between agriculture and climate, emphasizing the need to consider the impacts of climate change in a global context.  Simultaneously, other researchers like Hulme et al (1999) assessing climate change in terms of continuous changes in temperature and precipitation consider it as an additional factor that will have significant impact on agricultural productivity.  While one group of researchers (Rosenzweig et al, 1993) believes that impact of climate change on world food security as the reduced production in some areas are offset by increases in others, others (Matthews et al, 1995) hold that climate change will lead to a significant reduction in agricultural food productivity in developing countries.  For instance, according to one scenario, 34 countries are likely to suffer declines in crop production due to climate change (Lecture Notes, 2009).
In case the numbers displayed by Stern (2007) and IPCC (2007) are correct, climate change will affect crop yield via various changes, from temperature and soil moisture to precipitation and change in length of growing season.  Due to this the number of studies that predict and analyze the impact of climate change on agriculture across the different territories of the world has continued to increase since the early 1990s.  A major study by Matthews et al. (1997) on climate change and rice has estimated the potential impacts of equilibrium doubled CO2 climate change scenarios in many countries of Asia. This study found that rice production in the Asian region is estimated to decline by 3.8 percent in this century with substantial variations across the region.  Decline in yield has been predicted for Thailand, Bangladesh, southern China, and western India, while an increase is predicted
for Indonesia, Malaysia, Taiwan and parts of India and China.  This perspective is reinforced by global climate models that are disaggregated to examine the effects of global warming
in smaller regions (Saseendran et al., 2000).  From the critical perspective, impact of climate change on crop yields depend largely on technology and its improvements and innovations and farmers ability to adapt and respond to changing environmental conditions.  Therefore, it is still difficult to identify definite casuality between climate change and global agricultural development and world food security.  However, the majority of scientific evidence available points towards negative influence of continuous climate change on global agricultural sector.

In terms of its lasting consequences global climate change constitutes one of the most fundamental dilemmas for humanity.  This paper identified the main problems and critical moments associated with the problem of climate change and greenhouse effect and their continuous and potential impact on global agriculture and food security.  According to the majority of scientists, though this issue is still an ongoing scientific debate, greenhouse gas emissions are the main contributor to subsequent climate change.  To avoid this, emissions need to be considerably reduced in the short term in order to stabilize climate patterns and preserve a planet similar to that on which civilization developed and to which life on Earth is adapted (Hansen et al., 2008, p. 228). From the critical perspective, unfortunately there are still no universal international or sub-national policies, which would be effective in combatting greenhouse gas emissions. Largely referring to ineffectiveness of Kyoto Protocol, IPCC in one of its latest statements indicated that reducing emissions requires a portfolio of policies tailored to fit specific national circumstances (IPCC, 2007).