Climate change: Dual perspective

Dr Debapriya Mukherjee *

The current most concerned environmental problem is climate change with reference to global warming. It is an international challenge facing humanity in the 21st century. Since the last century, the average global surface temperature has risen by 0.74 °C (95% con?dence interval: 0.56–0.92 °C).

At the end of 2015, 195 nations adopted the Paris Agreement under the United Nations Framework Convention on Climate Change (UNFCCC), which focused on limiting the increase in the global temperature to less than 2 °C above pre-industrial temperatures and on framing efficient and sustainable policies to prevent the increase of temperature and carbon emissions. The Greenhouse gas emissions (GHG), especially carbon dioxide (CO2) emissions, are considered to be the main drivers of global warming.

The increase in atmospheric CO2 concentrations has reached 1.9 ppm (parts per million) per year, which has further exacerbated global warming. Deforestation and use of coal in cement, power and other industrial production are all pumping out CO2 into the atmosphere. Besides fossil fuels pumping out the harmful gases, natural weather fluctuations will exacerbate the problem as they hamper the ability of carbon sinks to store it. Cities are also responsible for three quarters of global energy consumption and greenhouse gas (GHG) emissions because more than half of the world population is living in the cities.

Additionally, a considerable amount of atmospheric GHG is produced through soil processes though these processes helps to consume CO2 but human activities alters the exchange of carbon (C) and nitrogen (N) between soil and atmosphere. Thereby CO2 is by far the biggest contributor to climate change.

The total world fossil energy-related CO2 emission was 11,190 million tonnes in 1965, but increased to 33,444 million tonnes in 2017, with an average annual growth rate of 3.75%.. IPCC’s research showed that the impact of climate change would continue for several centuries. If CO2 emissions are not controlled, the irreversible risks caused by climate change will increase in the future.

Frequent occurrences of air pollution and extreme weather conditions leading to floods and droughts as frequently being occurred in different parts of the world are the immediate and visible impacts generally associated with climate change. Crossing certain boundary of climate thresholds is expected to have serious consequences for humanity, including major changes in the Earth’s other systems, such as the water and geochemical cycles.

The above discussion clearly reveals that human activities is major factor for rising emission of CO2 inducing climate change but many scientists do not agree with that consensus. Though there is a growing consensus that climate is changing, but beliefs about the causal factors vary widely among the general public. Such causal beliefs are strongly in?uenced by cultural, political, and identity-driven views. As a result, the polarization of this climate debate has gone too far.

The climate lukewarmers belief that global warming is real, mostly man-made and will continue but it is not a planetary emergency because human ingenuity and prosperity will enable successful adaptation and that life for humankind will continue to improve as progress of climate change is slow and erratic so far. They also belief the IPCC process is flawed due to ideologically motivated scientists using evidence selectively and relying on flawed models.

They strongly advocated that climate change is not a catastrophe, investment is needed in adaptation not mitigation, and economic growth is necessary to ensure prosperity. They have argued that increased carbon dioxide levels in the atmosphere are beneficial to the biosphere and humanity by stimulating plant life, warming the planet and increasing rainfall. That has led to the idea that more CO2 in the atmosphere would be greener planet.

According to estimation made by the researchers the terrestrial biosphere through plants and soils absorbs about 25 per cent of anthropogenic carbon dioxide (CO2) emissions and helps the Earth to avoid some of the worst effects of climate change. Extrapolating this situation it may be expected that as levels of carbon dioxide increased, plants would soak up more of these emissions, helping to enhance their growth. The rate of land carbon uptake remains highly uncertain, leading to uncertainties in climate projections. Understanding the factors that limit or drive land carbon storage is therefore important for improving climate predictions.

One potential limiting factor for land carbon uptake is soil moisture, which can reduce gross primary production through ecosystem water stress, cause vegetation mortality and further exacerbate climate extremes due to land–atmosphere feedbacks. Recent study revealed that with the increase of temperature, plants and soil may start absorbing less greenhouse gas emissions instead of more. With the onset of drought the soil is dry; plants are stressed and cannot absorb requisite CO2 to perform photosynthesis.

At the same time, because dry conditions are often accompanied by warm temperatures, microorganisms in the soil, which are more productive when it’s warm, release more CO2. Though plants and soil could absorb more CO2 during the wetter years, it did not make up for their reduced ability to absorb CO2 in the years when soil was dry. Deforestation as being done in many places for industrial development will make this problem even worse.

The countries, such as India, Sri Lanka, Bangladesh, Pakistan and other developing countries with limited resources will be badly affected, on account of its huge population and levels of inequality and poverty. These countries are heavily dependent on the monsoon. The climate change as already observed is expected to alter weather patterns that, in turn, may cause uncertainty in availability of water for agriculture production.

In India, six hundred million people already face acute water shortage, according to government think tank Niti Aayog, with 54 per cent of India’s groundwater wells on a decline, and 21 major cities expected to run out of groundwater by 2020, affecting 100 million people. Sri Lanka, an equatorial island of 65,610 square kilometres (25,330 sq mi), is a biodiversity hotspot. It has 480 bird species (25 endemic) and 121 amphibious species (88 endemic).

Climate change is a threat to the island’s rich biodiversity, including its marine ecosystem and coastal coral reef environments. India, Sri Lanka and Bangladesh are particularly vulnerable to rising sea levels and weather-related disasters have the potential to set back any gains made in agriculture, fisheries and even services such as tourism. This could lead to decline of various ecosystem services that are indispensable for the welfare of human population. The increasing problems of poverty, ecosystem services degradation and climate change sensitivity in these countries are affecting global sustainable Development.

Based on contradictory arguments it is pertinent to mention that there are uncertainties in the science of global warming that may raise a question whether the forecast of danger on account of global warming is based on genuine science, or simply assumption. In this piquant situation, the major obstacle in mitigating the climate change is that citizens are relatively skeptical about increasing of earth temperature due to human activity and that will cause severe adverse impacts on the environment.

However it is a massive challenge but there are real opportunities to make an impact individually and globally. Whatever controversies are there on global warming, there must be regulations such as restrictions on gas emission and wastewater discharge from the plants that can play a significant role in addressing pollution control for clean environment. And climate change.