Too Much of a Good Thing? Global Warming

Concurrent with the spectacular increases in the earth’s population and the industrialization of civilization during the past 100 years, the earth’s usual air temperature has increased by about 1oF (0.6oC). This is called global warming. This may intensify the effect of greenhouse of the earth’s atmosphere through dramatic increases in concentration of greenhouse gases, especially CO2. Concentrations of carbon dioxide in the atmosphere have increased about 20 percent over the past 100 years and are expected to continue to increase. The increased carbon dioxide concentration is related to an imbalance in the carbon cycle due to human activity. This activity includes unnecessary use of fossil fuels in automobiles, manufacturing, agriculture and heating; deforestation of deciduous and tropical rain forests; and tillage of agricultural lands. Greenhouse gases related to agriculture include methane (CH4) and nitrous oxide (N2O). Methane is produced in fermentation reactions by ruminants like cattle, in manure holding areas, and in wetlands. In wet soils and wetlands the denitrification process produces nitrous oxide from the nitrate. Climate change, which is largely a result of burning fossil fuels, is already affecting the Earth’s temperature, precipitation, and hydrological cycles. Continued changes in the frequency and intensity of precipitation, heat waves, and other extreme events are likely, all which will impact agricultural production. Furthermore, compounded climate factors can decrease plant productivity, resulting in price increases for many important agricultural crops.

If recent trends persist, by the end of this century average air temperature are anticipated to increases by numerous degrees, depending on the increase in levels of greenhouse gases. While a few degrees may not seem like much, such increases in air temperature may cause changes in earth’s biomes; changes in crop production regions; and increases in extreme weather such as drought, thunderstorm, hurricane etc. According to projection of some scientists, sea level will ascend from 1 to 2 feet, which could force low-lying cities such as Mumbai etc. Higher air temperature have already been linked with the melting of polar ice caps and glaciers, reducing the habitation for many animals like polar bears, seals and penguins.

Global agriculture will be under significant pressure to meet the demands of rising populations using finite, often degraded, soil and water resources that are predicted to be further stressed by the impact of climate change. The ongoing buildup of greenhouse gases in the atmosphere is prompting shifts in climate across the globe that will affect agro-ecological and growing conditions. In addition, agriculture and land use change are prominent sources of global greenhouse gas emissions. The application of fertilizers, rearing of livestock, and related land clearing influences both levels of greenhouse gases in the atmosphere and the potential for carbon storage and sequestration. Therefore, whilst ongoing climatic changes are affecting agricultural production, the sector itself also presents opportunities for emissions reductions.

The net effect of climate change on world agriculture is likely to be negative. Although some regions and crops will benefit, most will not.

While increases in atmospheric CO are projected to stimulate growth and improve water use efficiency in some crop species, climate impacts, particularly heat waves, droughts and flooding, will likely dampen yield potential.

Indirect climate impacts include increased competition from weeds, expansion of pathogens and insect pest ranges and seasons, and other alterations in crop agro-ecosystems.

Weather these predictions will come to exceed is still a source of contention. Some do not believe climate change is happening ,while others think that even if the climate is changing, it is a natural event and not due to human activity. However, the majority of climate scientists are in accord that global warming is a real occurrence and the people throughout the world need to act to slow global warming. There is an opportunity to moderate global warming by changing human activities and adopting new practices. Potential solutions to reduce carbon dioxide in the atmosphere include reduction in fossil fuels uses by developing nations and using renewable fuels such as ethanol, halting deforestation of the tropical rain forests, increasing reforestations of agricultural landscapes, and increasing carbon sequestration of the soil through reduced or minimal tillage. Practices that minimize nitrogen fertilizer movement into surface waters can decrease nitrous oxide movement into the air.

About Author / Additional Info:
I have completed Ph.D. Agriculture in the discipline of Agronomy from Anand Agricultural University, Anand, Gujarat. I have also qualified national eligibility test conducted by ASRB, ICAR, New Delhi