Indubitably, climate change is a real existential threat, which has not only jeopardised the survival of the whole human race but also of flora and fauna. If this grave issue is not taken seriously, its consequences would be quite catastrophic, as underlined by premier Imran Khan in his address at 74th UNGA. The world should, therefore, make a common cause against this geological mayhem since it is the question of our safety and security as well as of our posterity. If we, God forbid, fail to arrest this colossal calamity in making, not to mention us, our future generation would also be suffering from the devastating effects of this global catastrophe, caused by our utter indifference and apathy. The climate can be described as the average weather over a while. “Climate change” means a significant change in the measures of climate, such as temperature, rainfall, or wind, lasting for an extended period – decades or longer. The Earth’s climate has changed many times during the planet’s history, with events ranging from ice ages to long periods of warmth. What’s different about this period of the earth’s history is that human activities are significantly contributing to natural climate change through our emissions of greenhouse gases. The factors contributing to climate change are of two types i.e. natural and the anthropogenic (human-induced). Naturally, climate changes due to the following reasons: Orbital changes: Earth has natural warming and cooling periods caused by Milankovitch cycles or variations in the tilt and/or orbit of the Earth around the Sun. If there is any change in such periods, it will cause a change in the earth’s climate. Volcanic activity: During a volcanic eruption, carbon dioxide is released into the atmosphere that results in global warming. Solar output: There can be fluctuations in the amount of radiation from the sun. If there is a high amount emitted, there will be an increase in Earth’s temperatures. However, anthropogenic factors causing climate change are of more concern than natural since they are contributing extensively to global warming and, hence, causing a great change in the overall atmosphere of the earth. Intergovernmental Panel on Climate Change (IPCC) affirms this fact that “Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic (produced by humans) greenhouse gas emissions.” Examples of human activities contributing to climate change include: Burning fossil fuels: coal, gas and oil release carbon dioxide into the atmosphere. Deforestation: Trees absorb carbon dioxide during photosynthesis. If they are cut down, there will be higher amounts of carbon dioxide in the atmosphere. Dumping waste in landfill: When the waste decomposes, it produces methane that contributes to global warming. Agriculture: Agricultural practices also lead to the release of nitrogen oxides into the atmosphere that aids global warming. The impact of global warming is so devastating that it might endanger not only human species but also all the biological kingdoms. Therefore, the future of the world seems precarious as projected by climate change experts. Climate models predict that Earth’s global average temperate will rise in the future. For the next two decades, warming of about 0.2° Celsius is projected. If we continue to emit as many, or more, greenhouse gases, this would cause more warming during the 21st Century than what we saw in the 20th Century. During the 21st Century, various computer models predict that Earth’s average temperature would rise between 1.8° and 4.0° Celsius (3.2° and 7.2° F). Climate change is predicted to impact regions differently. For example, temperature increases are expected to be greater on land than over oceans and greater at high altitudes than in the tropics and mid-latitudes. Warmer average global temperature will also cause a higher rate of evaporation; causing the water cycle to “speed up.” More water vapour in the atmosphere would lead to more precipitation. According to models, global average precipitation would most likely increase by about three to five per cent with a minimum increase of at least one per cent and a maximum increase of about eight per cent. Yet, changes in precipitation will not be evenly distributed. Some locations will get more snow; others will see less rain. Some places will have wetter winters and drier summers. Moreover, as the climate warms, snow and ice also melt. The amount of summer melting of glaciers, ice sheets, and other snow and ice on land is predicted to be greater than the amount of winter precipitation. The amount of sea ice (frozen sea water) floating in the ocean in the Arctic and Antarctic is expected to decrease over the 21st Century too, although there is some uncertainty as to the amount of melt. To add, earth’s oceans are predicted to act as a buffer against climate change by taking up some of the excess heat and carbon dioxide from the atmosphere. This is good news in the short run, but more problematic in the long run. Carbon dioxide combined with seawater forms weak carbonic acid. Scientists believe this process has reduced the pH of the oceans by about 0.1 pH since pre-industrial times. Further acidification of 0.14 to 0.35 pH is expected by the year 2100. More acidic ocean water may cause problems for marine organisms. Some climate scientists also believe that hurricanes, typhoons, and other tropical cyclones will (and may have begun to already) change as a result of global warming. Warm ocean surface waters provide the energy that drives these immense storms. Warmer oceans in the future are expected to cause intensification of such storms. “Climate change is one of the greatest challenges facing humanity, and it is the world’s most vulnerable populations who are most immediately at risk. The actions of the wealthiest nations-those generating the vast majority of greenhouse gases-have tangible consequences for people in the rest of the world, especially in the poorest nations.” (Michel R. Bloomberg) Additionally, Climate change will also alter many aspects of biological systems and the global carbon cycle. Temperature changes will alter the natural ranges of many types of plants and animals, both wild and domesticated. There will also be changes to the lengths of growing seasons, geographical ranges of plants, and frost dates. Models of the global carbon cycle suggest that the Earth system will be able to absorb less CO2 out of the atmosphere as the climate warms, worsening the warming problem. Pakistan is also one of the worst-hit countries of the world by climate change. PM Imran Khan, while addressing the 74th UNGA, also voiced the same concern; saying that Pakistan was the seventh most vulnerable country in the world to global warming despite that it contributed less than one per cent to the total greenhouse gas emissions. A World Bank report, “Pakistan’s Hotspots – The Impact of Temperature and Precipitation Changes on Living Standards,” released in July 2018, claimed that by 2050, annual average temperatures were projected to increase to 2.5°C under the climate “sensitive scenario” (which represents a future in which some collective action is taken to limit greenhouse gas emissions) and up 3.0°C under the carbon “intensive scenario” (in which no serious actions are taken). Approximately 49 million or 25 per cent of Pakistan’s total population, lives in locations that will become “moderate hotspots” by 2050 under the carbon-intensive scenario. Therefore, containing the temperature is essential to prevent major areas of Pakistan from becoming uninhabitable in a future not too far away. What is more, to worry is that climate change poses a serious threat to the living standards of the vast population of Pakistan. The report further indicates Sindh province as the most vulnerable hotspot. With a GDP per capita of US $1,400, Sindh is the second-largest economy of Pakistan and contributes 30 per cent to the national GDP. Its economy is highly diversified, ranging from heavy industry and finance centred in and around Karachi to a substantial agricultural base along the Indus River. Changes in precipitation and temperature threaten to impede the future growth of this region. According to the report, Hyderabad district in Sindh emerges as the top hotspot, followed by Mirpur Khas and Sukkur districts. The second most vulnerable hotspot is the densely populated province of Punjab. Punjab has the largest economy, contributing 53.3 per cent to Pakistan’s GDP, and is known for its relative prosperity with the lowest poverty rate of all the provinces. However, its wealth is unevenly distributed, with the northern portion being relatively well off economically and the southern portion being one of the most impoverished areas in the country. Long-term climate vulnerability thus carries implications for both shared prosperity and poverty reduction of this province. Interestingly, some of the most densely populated cities – including Lahore, Multan, and Faisalabad – emerge among the top 10 hotspot districts. This indicates that we must prepare not only the more impoverished areas for the adverse effects of climate change, but also protect the economic hubs of the provinces. Inter alia, with the changing cropping calendar, and more erratic and unpredictable monsoon season, Pakistan’s food insecurity is also under increasing threat of climate change. We are also, on one hand, fast losing our coastline to seawater intrusion, while at the other, glaciers are fast melting, resulting in permanent reductions in water flows in our rivers. The swelling unpredictability in river flows has also made planning for hydro-energy much more difficult and unreliable. As environmental degradation takes place, livelihood options shrink, forcing people to migrate to cities in search of economic opportunities. Climate-induced migration has already made Pakistan one of the most urbanized counties in South Asia. In the light of preceding discussion, it can be safely concluded that climate change is a serious threat to the world therefore, it requires collective efforts of all the stakeholders to make a synergy against this global geological mayhem since it is not only a matter of our survival but also of our posterity, That’s why we must act together to meet this imminent challenge effectively. The premier Khan, in his address at 74th UNGA, also suggested to the world community that climate change is something, which cannot be dealt with by any individual country until the world gets together. The writer is a legal practitioner-cum-columnist based in Quetta, Balochistan