CLIMATE CHANGE

Causes, effects, evidence and how to deal with it

Sajad Ali Jatoi

Climate means average weather pattern of a particular area over a long period of time – at least thirty years, while Climate change refers to the long-term shift in global average weather patterns i.e. changes in temperature, precipitation and rainfall patterns. These changes in climate are directly or indirectly induced by human activities such as expansion of greenhouse gas emissions, land use, deforestation and degradation of forests. The changes are transpiring irrespective of any region, country or continent and will have global impacts. Both developing and developed countries are vulnerable to the wide-ranging consequences of Climate change. Everyone in the world is going to be affected by it. Ban Ki-moon, who served as the eighth secretary general of the United Nations, once talking about the Climate change said: “Climate change does not respect national borders”.

 Most of the people confuse climate change with global warming and assume that both are the same. In fact, global warming constitutes just one aspect of climate change, as global warming means rise in global average temperature, whereas climate change entails global warming, air pollution and other such things.

Despite the evidence and explanations provided through scientific researches, there are people who are of the opinion that Climate change is not real and term it fake. Their refusal to accept it is nothing but the denial of the stark fact. There have been numerous things observed which allay suspicion about climate change. More prominently, rise in global average temperature also called global warming confirms this assumption. NASA, showing the evidence for Climate change, posted to its official website as: “The planet’s average surface temperature has risen about 1.62 degrees Fahrenheit (0.9 degree Celsius) since the late 19^th century”. In addition to it, global warming has caused oceans to absorb the heat—coming in the form of sunlight. Data from various researches show that since 1969, surface of oceans, up to 700 metres deep have warmed up about 0.4 degrees Fahrenheit.

Moreover global sea level rise attests to the fact that the climate is going through changes. Intergovernmental Panel on Climate Change (IPCC) a United Nations body for assessing research on Climate change, in its fifth assessment report shows that global mean sea level has risen about 0.19 metres. Besides, ocean acidification, glacial retreat and decreased snow cover are the other things which substantiate the evidence for Climate change. Oceans have increased in acidity due to the increased uptake of CO₂. IPCC’s fifth assessment report says “pH of ocean surface water has decreased by 0.1 (high confidence), corresponding to 26% increase in acidity”.

         All of the observed changes are anthropogenic—human-induced. The fundamental things which are driving Climate change is the presence of greenhouse gases and aerosols in Earth’s atmosphere. Aerosols are tiny particles floating in the atmosphere which are released through both natural and anthropogenic processes. Aerosols can be dust particles, minute droplets and tiny bits of carbon and other such things. They collect in the atmosphere through natural and human sources. Dust, for example, comes from dry lands, deserts and dried-out river banks. Carbon particles are shot into the atmosphere when volcanoes erupt explosively. Anthropogenic activities contribute to the atmospheric aerosol amount in many ways. For instance, fossil fuel burning, besides greenhouse gases, produces carbonaceous particles. Major Man-made aerosols—sulfate—are released into the atmosphere when tropical forests, coal, etc are burned. Agriculture produces dust—when farmers plough the fields. Scientists are sure that their amount has increased since the industrial revolution began. Aerosols have influence on climate. Increase in their amount can either cool or warm up the planet. They alter the whole energy equilibrium of the Earth as they float in the atmosphere. In addition, they pollute air and do harm to ozone layer. Greenhouse gases are released into the atmosphere from fossil fuel burning, land use, irrigated agriculture, animal husbandry, oil extraction and deforestation. All of these activities are anthropogenic and add to the atmospheric greenhouse effect. Presence of greenhouse gases in Earth’s atmosphere is responsible for its suitability for life. If these gases had not been present, it would not have been possible for any organism to live on Earth. Like decrease, extreme increase in their amount is harmful for life, because this leads to greenhouse effect. Greenhouse effect is a natural process that warms the surface of the Earth. The Earth gets its energy from the Sun. when sunlight reaches Earth some of it is reflected back into space and the rest is absorbed by the land and oceans. The absorbed heat is radiated back into space, but greenhouse gases trap it and reradiate it towards Earth, thereby causing it to warm up. As greenhouse gases are collecting in the atmosphere, the greenhouse effect is increasing and bringing about global warming. Greenhouse gases comprise CO₂, methane, Nitrous oxide, water vapours and chlorofluorocarbons. Carbon dioxide, the most long-lived forcing of Climate change, is released into the atmosphere mostly because of fossil fuel burning —coal and oil.  It is a small component of the atmosphere, as it makes less than 0.5% of the total atmospheric gases, but it is of great significance. Increase in its amount is going to be catastrophic for all life on Earth. Researches show that its concentration has increased since the Industrial revolution began. NASA says that the concentration of CO₂ in Earth’s atmosphere is currently at nearly 414 parts per million (ppm) and rising. This represents a 48 percent increase since the Industrial revolution began, when the concentration was near 280 ppm. Methane also called natural gas, is a hydrocarbon gas and is released through both natural and anthropogenic ways; these include agriculture, decomposition of wastes in landfills and manure management. In agriculture, rice cultivation is responsible for methane release.  Nitrous oxide is produced from both natural and human sources and its concentration has increased by 16% since the beginning of Industrial revolution. Anthropogenic sources such as agriculture and combustion of biomass and fossil fuels are responsible for its emissions and as well as natural sources like volcanoes.

    Climate change will affect every aspect of life, including agriculture, water resources, forests, biodiversity, sea level, coastal areas and human health. But the prominent and challenging effect of it is the depletion of ozone layer. Ozone layer protects life from Ultra violet rays, otherwise which could destroy it. Increase in atmospheric CFCs is triggering ozone depletion. When ultra violet rays from the Sun hit CFCs in the stratosphere, carbon-chlorine bonds break, resulting in free chlorine atoms. The chlorine atoms react with ozone molecule (O3) which leads to the destruction of ozone layer.

      In agriculture, it is likely that food growing regions change in the future. Regions where crops, such as rice, do not grow because of cold climate will become cultivable due to global warming and vice versa. Moreover, crop yields would also be affected — pests, crop diseases and demands for irrigation would pose a challenge for agriculture. Scientists have predicted that crop yields would decrease in the coming times. Climate change would also disrupt forest economy and cause modifications in natural forests. Some of them might disappear owing to increasing bushfires from drying and loss of humidity. Forests act both as a cause and solution for climate change. Changes in their location and disappearance would affect biodiversity. Some of the species that inhibit tropical forests run the risk of extinction. Further, increase in temperature and air pollution will have bearings on water resources. It may lead to either drought or flooding, both of which are not in the interests of human beings. Water quality is likely to be affected as well. Besides the effects mentioned, coastal areas are on the line as sea levels are rising. This effect would disrupt life on a large scale, as most of the metropolitan cities of the world lie around coastal regions.

    All of the mentioned impacts, thus far, will have negative implications for human life. Rise in temperature, disruption in agriculture, changes in water resources, disappearance of forests, immersion of coastal areas and other factors will stimulate migration and as well as affect food security, human health and global economy. People will migrate to areas where they can find sustenance. Migration will breed the problems of employment and housing. Subsequently, these problems will lead to crimes —thefts, robberies and killing. In the future, it might be impossible for agriculture to meet the demands of people, for crop yield is declining and contrary to this, human population is rising. Human health will be affected; global warming will precipitate heat waves, thereby leading to increase in mortality. Certain diseases, such as vector-borne Malaria and Dengue will escalate and spread to temperate areas. Besides this, climate change poses a big threat to global economy.

    There are two ways to tackle climate change: mitigation and adaptation. Mitigation – reducing climate change – entails reducing the emissions of greenhouse gases into the atmosphere and promoting renewable energy sources. This objective can be achieved by reducing the sources that emit heat-trapping gases and enhancing the sinks that accumulate these gases. In order to reduce the sources that emit them, we need to cut fossil fuel burning by limiting the usage of transportation, heat and electricity in our daily lives. Every single person in the world has a party to play. We as an individual should prefer to use public transport instead of driving our own cars, and should use them occasionally, if necessary. We should also avoid the unnecessary use of electrical appliances such as light bulbs. On the surface, this might seem ridiculous and may not make sense to an ordinary man. It is likely that he/she has a question on his/her mind that how can this stop the unavoidable climate change. In fact, we are all contributing to it as an individual. Though, this effort cannot stop climate change altogether, it will certainly slow down it. We can also control the amounts of greenhouse emissions by promoting sinks – afforestation, as trees play a pivotal role in controlling the amount of carbon dioxide in the atmosphere. Mangrove trees, for example, are one of the best sinks to store carbon. They can store it four times more than rainforest trees do. It is estimated that 50 mangrove trees can absorb about 1 metric ton of carbon dioxide.  Furthermore, promotion of renewable energy sources will be helpful in mitigating climate change, for it is clean and does not involve combustion or anything like that. It is derived from natural sources, for example solar energy is generated from the sunlight; wind energy from wind and hydropower from water. After mitigation, adaptation is another thing which can assist in curbing climate change. By adaptation I refer to the anticipation of adverse effects of climate change and adjusting to expected climate by taking practical actions. We need to observe the changes that have taken place; plan things and take action accordingly. We need to build defense system against natural disasters. We should use scarce water resources more efficiently and raise the dykes of rivers which might overflow because of glaciers melting at faster rates. In the end, raising general awareness about the implications of climate change will also be helpful and it is a responsibility of everyone who is well aware of it to further this noble cause among the masses about the impacts of climate change. It is a battle, which we will not be able to win, if the ordinary people stay away from it.

CONCLUSION:

Climate change implies changes in global weather patterns—changes in temperature, precipitation and rainfall patterns. These changes are happening regardless of region, community, country or continent and are likely to affect every human being living on this planet. In the last fifty years some of the changes as forecast by earlier scientists, have started to take place, which can be used as a proof that climate changes is real. The observed changes include rise in global temperature i.e. global warming, global mean sea level rise, shrinking ice sheets and glacial retreat to name but a few. The changes will increase in severity in the recent future and will have impacts on life.  They pose many threats to it and can disrupt it terribly. The major threats, which climate change is likely to bring about are: extinction of certain species, depletion of ozone layer, removal of and modifications in the locations of tropical forests, decrease in yields in agriculture sector and for humans, food security and human health are on the line. The cardinal cause of these changes as scientists believe, are human beings themselves. Humans increased greenhouse gas emissions and amount of aerosols in the atmosphere. Increase in their amount is precipitating climate change. Therefore, in order to tackle climate change we need to cut emissions of greenhouse gases; promote renewable energy sources and take other preventive measures. Switching from non-renewable energy sources to renewable ones is the only thing which can help us halt climate change. For this purpose, there have been so many agencies working on it at regional, national and international level, but they will not be effective, if we do not cooperate and play our part. Therefore, it is high time we did something to halt it and secure the future of coming generations; pass on to them an intact and habitable world.