Climate change can generally be defined as a change in global or regional climate patterns. In particular, it is the change apparent from the mid-to-late 20th century onwards, and attributed largely to the increased levels of atmospheric carbon dioxide produced by the use of fossil fuels. The Framework Convention on Climate Change (UNFCCC), in its Article 1, defines climate change as: “A change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods.” Climate change has caused drastic effects in the world climate, such as the rise of carbon dioxide level, global temperature, melting of ice sheets, rise of sea levels, and ocean acidification. For this change,a range of human activities is responsible. As per NASA, 97 percent of climate scientists agree that climate-warming trends over the past century are very likely due to human activities, for instance, the rapid emission of carbon dioxide that has resulted in global warming. We, therefore, need a broad-based consensus at international level and a firm commitment at the national level to fight to diminish the aftermath of climate change. Human activities are the major cause of climate change. The foremost cause is global warming. Burning fossil fuels, such as coal and oil, has increased the concentration of carbon dioxide. Due to expansion of the greenhouse effect, global warming has risen. As per this phenomenon, gases such as water vapors, carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons in the our atmosphere prevents the heat to leave the earth’s atmosphere; resultantly, the ozone layer depletes and the temperature rises. In its Fifth Assessment Report, the Intergovernmental Panel on Climate Change (IPCC) concluded that there is a more than 95 percent probability that human activities over the past 50 years have warmed our planet. Industrial activities that our modern civilisation depends upon have raised atmospheric carbon dioxide levels from 280 parts per million to 400 parts per million in the last 150 years. The panel also concluded there is a better than 95 percent probability that human-produced greenhouse gases such as carbon dioxide, methane and nitrous oxide have caused much of the observed increase in earth’s temperatures over the past 50 years. About half of the CO2 emissions, between 1750 and 2010, have occurred in the last 40 years. Deforestation and increase in the use of chemicals in domestic and agriculture life is another reason of climate change. Deforestation is the second leading cause of global warming and produces about 24 percent of global greenhouse gas emissions. Scientists say that deforestation in tropical rainforests adds more carbon dioxide to the atmosphere than the sum total of all the cars and trucks on the world’s roads. The surge in the uses of chemicals in domestic as well as in agriculture, in the shape of fertilisers, also plays its role in climate change. The high rate of application of nitrogen-rich fertilisers has effects on the heat storage of cropland (nitrogen oxides have 300 times more heat-trapping capacity per unit of volume than carbon dioxide) and the run-off of excess fertilizers creates ‘dead zones’ in our oceans. In addition to these effects, high nitrate levels in groundwater due to over fertilization are cause for concern for human health. These causes resulted in climate change and have a perilous aftermath. In this regard, the Intergovernmental Panel on Climate Change (IPCC) was created by the United Nations Environment Programme (UN Environment) and the World Meteorological Organisation (WMO) in 1988. It now engages with 195 member countries, which provides policymakers with regular scientific assessments on climate change, its implications and potential future risks, as well as to put forward adaptation and mitigation options. The foremost hazardous evidence is the rise of carbon dioxide in out atmosphere. As per NASA’s scientific evidence, for a millennium, the level of carbon dioxide (parts per million) was below 300, which started to rise since 1950, and is now above 400. Secondly, as per NASA’s evidence, the planet’s average surface temperature has risen about 1.62 degrees Fahrenheit (0.9 degrees Celsius) since the late 19th century, a change driven largely by increased carbon dioxide and other human-made emissions into the atmosphere. Most of the warming occurred in the past 35 years, with the five warmest years on record taking place since 2010. This is also established by the United Nations’ report, prepared by the World Meteorological Organisation, on September 22, 2019. It states that the period “is currently estimated to be 1.1 degrees Celsius above pre-industrial era of 1850-1900, and 0.2 degrees Celsius warmer than 2011-2015”. Thirdly, the oceans are getting warmer, and ice sheets are shrinking. As per NASA, the oceans have absorbed much of this increased heat, with the top 700 meters (about 2,300 feet) of ocean showing warming of more than 0.4 degrees Fahrenheit since 1969. The Greenland and Antarctic ice sheets have decreased and have lost an average of 286 billion tons of ice per year between 1993 and 2016, while Antarctica lost about 127 billion tons of ice per year during the same time period. The rate of Antarctica ice mass loss has tripled in the last decade. Fourthly, the glaciers are melting and sea level is rising. Around the globe, the glaciers are retreating including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa. The global sea level rose about eight inches in the last century. The rate in the last two decades, however, is nearly double that of the last century and is accelerating slightly every year. There are other drastic evidences of climate change. Arctic sea ice is declining rapidly. Disturbed rainfalls and extreme weather events have increased. Also, the ocean acidification, which has increased by about 30 percent since the Industrial Revolution, is another evidence of climate change. It also has a negative impact on crop yield productions. The direct impact on the lives of humans is on the vulnerable and the marginalised segment of society. As per NASA, 97 percent of climate scientists agree that climate-warming trends over the past century are very likely due to human activities As per IPCC Fifth Assessment Report, numerous risks are involved that raise concern. These include risk of death, injuries, health or disturbed livelihoods due to storms, flooding and sea-level rise. The risk in water supply, supply of electricity and emergency situations are also there. The foremost risk is food insecurity due to droughts, flooding, and precipitation variability. There is the risk to lose marine and coastal ecosystems and biodiversity as well. Although Pakistan is not much contributing in global warming and climate change, yet it is the seventh most affected country. The Global Change Impact Studies Centre of Pakistan shows that the mean annual temperature has increased in the recent past with greater increase in Sindh and Balochistan. During the last century, the average temperature over Pakistan has increased by 0.6°C, which is in conformity with the increase of the average global temperature. Future climate change projections, based on all four IPCC-AR5 RCPs scenarios, show that the average rise in temperature over Pakistan, by the end of the century, will be about 1°C higher compared to the global average. This increase, particularly in temperature, is associated with a number of adverse impacts, including the increasing frequency of extreme events (floods, droughts, heat waves, and cyclonic activity), steady regression of most glaciers (except a small minority in the Karakorum Range) that supply the bulk of the country’s water supply and changes in the rainfall patterns. Pakistan’s water cycle is the primary affected area of climate change. Agriculture is one of the major sectors likely to be adversely affected by climate change. Climate change can disrupt food availability, reduce access to food, and affect food quality. Projected increases in temperatures, changes in precipitation patterns, changes in extreme weather events, and reductions in water availability may all result in reduced agricultural productivity. Seasonal smog is also due to climate change and pollution. Pakistan has also suffered economically due to climate change. According to experts, Pakistan has faced around 150 freak weather incidents as a result of climate change in the past 20 years: flash floods, smog in winter, forest fires in summer, melting glaciers, freaky heatwaves, landslides, displaced population. During the floods in 2010-11, almost 10 percent of Pakistan’s population was displaced in two provinces, one in the north and another in the south. Last year, the cost of extreme weather as a consequence of climate change was listed at $384 million; in the past 20 years, there has been a cost of almost two billion dollars to the national economy because of the ravages of climate change. The writing is on the wall. The world is responding to the danger now. Greta Thunberg, a teenage Swedish environment activist, shookup the top leaders with a Global Climate Strike call on September 20, 2019, through which the protest was recorded in around 150 countries, in more than 4,500 places. The UN has shown its commitment to fight in this noble cause. There are various agreements and protocols for climate change. The United Nations Framework Convention on Climate Change (UNFCCC) is the main international agreement on climate action. It was one of the three conventions adopted at the Rio Earth Summit in 1992. To date, it has been ratified by 195 countries. It started as a way for countries to work together to limit global temperature increases and climate change, and to cope with their impacts. In the mid-1990s, the UNFCCC signatories realised that stronger provisions were needed to reduce emissions. In this regard, they agreed to the Kyoto Protocol in 1997, which introduced legally binding emission reduction targets for developed countries. Next comes the Paris Agreement; the Paris climate conference took place from November 30 to December 11, 2015. On December 12, the parties reached a new global agreement on climate change. The agreement presents a balanced outcome with an action plan to limit global warming ‘well below’ two degree Celsius. There is also the Montreal Protocol 1987, which is a global agreement to protect the stratospheric ozone layer by phasing out the production and consumption of ozone-depleting substances. There is also the United Nations Convention to Combat Desertification (UNCCD) 1994 to combat desertification and mitigate the effects of drought in countries experiencing serious drought/ desertification. What requires is that we must change course by 2020, as the UN Secretary General Antonio Guterreshas said; we risk missing the point where we can avoid the “disastrous consequences for people and all the natural systems that sustain us.” In this regard, there are the following suggestions to tackle global warming. Dramatically reducing our use of fossil fuels, especially carbon-intensive coal, is essential to tackle climate change. There are many ways to begin this process. Key action steps include: not building any new coal-burning power plants, initiating a phased shutdown of coal plants starting with the oldest and dirtiest, and capturing and storing carbon emissions from power plants. While it may sound like science fiction, the technology exists to store carbon emissions underground. Taken together with the tropical deforestation, emissions from agriculture represent nearly 30 percent of the world’s heat-trapping emissions. We can fight global warming by reducing emissions from deforestation and forest degradation and by making our food production practices more sustainable. Using alternative sources of energy is more efficient and meets the problem of global warming. Energy producing from solar, wind, tidal, and biomass are more clean and renewable. There are least effects if we produce electricity from the alternative sources of energy. Nuclear power results in a few global warming emissions; an increased share of nuclear power in the energy mix could help reduce global warming. A successful global compact on climate change must include financial assistance from richer countries to poorer countries to help make the transition to low-carbon development pathways and to help adapt to the impacts of climate change. The energy used to power, heat, and cool our homes, businesses, and industries are the single largest contributor to global warming. Energy efficiency technologies are the dire need of the hour. Transportation sector’s emissions have increased at a faster rate than any other energy-usingsector over the past decade. For this, efficient fuel consumption modes of transport, and switching to low-carbon fuels are the requirement of time. In a nutshell, we must develop a two-pronged approach: firstly, we must reduce emissions and stabilise the levels of greenhouse gasses in our atmosphere; secondly, we must adapt climate-friendly lifestyles and pursue the principles of sustainable economic growth. Although Pakistan is facing environmental challenges, which include climate change impacts, loss of biological diversity, deforestation and degradation of air and water quality, Pakistan is trying to respond well. Because of the deteriorating economy, the country could not do much. But still, the present government has launched the Ten Billion Trees Tsunami Programme to lead the country towards aiming at revival of forestry and control air, weather, wildlife, forestation, watershed management and soil conservation to combat the negative impacts of climate change. Pakistan is amongst the pioneers who have established a climate ministry. The country has also launched the Climate Change Policy 2012. The National Climate Change Policy comprehensively addresses all possible challenges of climate change and provides a foundational framework to tackle the problem. But Pakistan alone cannot do it. It is a global issue. The whole of the world’s future is at stake. It is time that the United Nations, along with all 195 countries, do not let the grass grow under its feet and act now to save the mother earth. The writer is an advocate of the High Court and teaches law