Since the second half of the twentieth century, climate change has become a major concern among scientists, politicians, and environmentalists alike. Climatic changes have occurred over the course of the earth’s history due to natural processes. Such changes were gradual over a long period. Over the last 50 years, global temperatures have been on the rise at higher rates and much faster causing a major concern to humanity. Indeed majority of the hottest years since temperature recording started have been in the last fifty years. It is projected that 2015 will go down as the hottest year ever since recording temperature started. The increase is attributed to human activities. The changes occurring puts humanity in danger of extinction due to excessive temperatures, water scarcity, food scarcity due to encroaching deserts and flooding arising from melting glaciers. The severity of the consequences has made the issue of curbing climatic changes a concern to scientist, media, environmentalists, civil society, and politicians alike.
Human activities lead to the generation of gases known as Greenhouse Gases (GHG) because they trap heat just as the greenhouses used in crop farming. The major gas that contributes to global warming and thus climatic changes is the CO2, and to a lesser extent nitrous oxide and methane. These gases absorb radiation emanating from the surface of the earth, clouds, and gas molecules trapping it as heat in the lower atmosphere.
The GHCs gases exist naturally in the atmosphere and play an important role in regulating temperatures to avoid burning up during the day and freezing out at night. Naturally, these gases would balance themselves. However, rapid population increase since the 1960s has led to increased human activities such as industrialization, deforestation, agricultural development, mining and extraction of fossil fuels besides burning them have increased the levels of GHCs in the atmosphere. The result is a disruption of the atmospheric balance. The increased GHCs trap more heat leading to a warming effect on the earth surface. Since gases easily move over the whole earth, the warming effect is spread globally leading to what is referred to as global warming that results into man-made climatic changes. The climatic changes cause significant changes globally.
A rise in sea level due to increased flow of freshwater emanating from melting snow and ice is a major effect of climatic change. The expanding volumes of warm water wreak havoc on fish stocks and other aquatic living things. This translates into lost livelihoods for those who depend on fish and seafood to make a living. It contributes to lost income, food insecurity, malnutrition, and poverty among others. The rise in sea levels endangers most of the cities and towns located along the coastline as they are at the risk of being submerged by the rising water levels.
The other major effect is the increasing variability of rainfall resulting into dangerous flooding, droughts and unpredictable seasons. Floods wreak havoc among those who live close to rivers and other water bodies resulting into immense economic loss and in some cases loss of life. Droughts and famines have increasing in frequency and intensity due to climatic changes. Expanding deserts have encroached on land that was previously productive. The communities living in those geographical areas lose livelihoods and suffer from the effects of drought such as malnutrition, diseases, and on the extreme death. For example, the Sahara desert in Africa has expanded over the years encroaching on land that was previously productive. In the process, the inhabitants of the land taken by desert have lost livelihood and become dependent on aid.
The reduced predictability on seasons is detrimental to the farming communities since it is impossible to know with certainty what to plant when. Floods resulting from increased rainfall lead to destruction of infrastructure such as roads, bridges, electricity grid among others. This results into economic loss due to costs of repairs and lost economic opportunities. This is evident across the globe where unusual rainfalls, snow and storms wreak havoc. Droughts and famines have also increased across the globe in the last fifty years leading to loss of economic opportunities and life. The higher temperatures on the earth’s surface both land and sea is detrimental to life. As the climate changes, the likelihood of some plants and animals becoming extinct increases. Increased levels of CO2 in the atmosphere result into more acidic oceans as the CO2 dissolves easily in the warm ocean waters. The increase in acidity would have negative effects on aquatic life and the oceans’ ecosystems.
CO2 is the most prevalent anthropogenic greenhouse gas. Its concentration in the atmosphere has increased from the value of 280ppm in the pre-industrial period to 3799ppm3 in 2005. The concentration of CO2 in the atmosphere in 2005 exceeded the natural range for the previous 650,000 years, which was 180 – 300 ppm. The measurements are determined from ice cores. Use of fossil fuel is the greatest contributor to the increase of CO2 concentration in the atmosphere. Land use contributes a smaller but significant portion of the concentration.
Methane atmospheric concentration globally increased from 715ppb in the pre-industrial time to 1732 ppb in the early 1990s, further increasing to 1774ppb in 2005. The natural range for the last 650,000 years ranged from 320 to 790 ppb according to ice cores. Predominantly use of fossil fuels and agriculture account this increase. The concentration of nitrous oxide in the global atmosphere equally increased from 270 ppb prior to the industrial revolution to 319 ppb in 2005. More than a third of the gases’ emission is attributable to agricultural activities.
Because of climatic changes, snow cover such as on mountains is projected to contract. Sea ice in the Arctic and Antarctic is projected to shrink due to melting glaciers and icebergs. Heat waves, storms, and heavy rainfalls are projected to increase in frequency and intensity. Typhoons and hurricanes would become more frequent as already evidenced from the last twenty years.
Human being can prevent global warming effects by choosing the use of renewable energy that generates its power from wind or solar energy. Second is the reduction of fuel consumption by use of smarter cars and increasing car fuel efficiency. Third is the use of solar energy for heating to save on electricity and money. Fourthly, human being should conserve energy by not lighting during the day, switching off electric appliances when not in use, and using fluorescent bulbs rather than incandescent light bulbs. Lastly, human being can reduce global warming by reducing deforestation and develop a habit of planting trees around homes. The trees will provide shades during summer and at the same time absorb carbon dioxide in the atmosphere.
Although a single weather event is not attributable to man-made climatic changes, the number and intensity of storms, floods and droughts has dramatically increased since 1960. This is a clear indicator that climate change is real and drastic measures are needed to reverse the effects. Failure to take measures to reverse the adverse effects and to address the causes will lead to adverse effects on humanity, animal and plant life and over many years possibly extinction.