The most important issue of our day is climate change, and this is a pivotal period. The effects of climate change are unparalleled in magnitude, ranging from changing weather patterns that endanger food production to increasing sea levels that increase the likelihood of catastrophic flooding. Without immediate action now, future adaptation to these effects will be more difficult and expensive.
Greenhouse gases occur naturally and are essential to the survival of humans and millions of other living things
Because they prevent some of the heat from the sun from bouncing back into space and make the Earth habitable, greenhouse gases are a natural occurrence and are vital to the life of people and millions of other living creatures. But as a result of industrialization, deforestation, and large-scale agriculture that has lasted for more than a century and a half, the amount of greenhouse gases in the atmosphere has reached record heights that haven't been seen in three million years. The total amount of greenhouse gas (GHG) emissions rises along with population, economy, and living standards.
There are a few fundamental, well-known scientific connections:
The amount of GHGs present in the earth's atmosphere is directly related to the planet's average global temperature;
Since the Industrial Revolution, both the concentration and the average world temperature have been gradually increasing;
Carbon dioxide (CO2), the most prevalent GHG and the source of around two thirds of GHGs, is mostly produced by the combustion of fossil fuels.
The UN Intergovernmental Panel on Climate Change (IPCC)
The World Meteorological Organization (WMO) and United Nations Environment created the Intergovernmental Panel on Climate Change (IPCC) to serve as an impartial source of scientific data.
Climate Change 2021: the Physical Science Basis
In every region and throughout the entire climate system, the Earth's climate is changing, according to the IPCC's most recent scientific assessment. In tens of thousands, if not hundreds of thousands of years, many changes have not occurred. Some have an irreversible effect lasting hundreds to thousands of years, such as persistent sea level rise.
The report asserts unequivocally that human influence on the climate system has a significant role. It also demonstrates that human actions still have the power to influence how the climate will develop in the future, and it highlights the need for significant and sustained reductions in carbon dioxide and other greenhouse gas emissions. While improvements in air quality would be noticeable right away, stabilizing global temperatures would take 20 to 30 years. The report is the first in a series building up to the IPCC Sixth Assessment Report in 2022. It was released by the IPCC's Working Group I and authorized by 195 member nations.
It expands on developments in linking certain weather and climate occurrences to climate change and takes a closer look at the regional aspects of climate change. Read the physical science quick facts for more details.
Fifth Assessment Report
The report offers a thorough analysis of the causes of sea level rise during the previous few decades. Additionally, it provides a CO2 budget for anticipated future emissions in order to keep warming to less than 2°C and calculates total CO2 emissions going back to pre-industrial periods. By 2011, about half of this maximum amount had already been released. The study discovered that:
The average global temperature rose by 0.85°C between 1880 and 2012.
Sea levels have increased, snow and ice cover has decreased, and oceans have warmed. The average global sea level increased by 19 cm between 1901 and 2010 as a result of ocean warming-induced ocean expansion and glacier melt. Since 1979, the Arctic sea ice extent has decreased, with an average ice loss of 1.07 106 km2 each decade.
The probability that the average global temperature will continue to increase above pre-industrial levels by the end of this century is high given the current concentrations and continuous emissions of greenhouse gases. Oceans around the world will warm, and ice will keep melting. According to predictions, the average sea level will rise by 24–30 cm by 2065 and 40–63 cm by 2100 in comparison to the 1986–2005 reference period. Even if emissions are reduced, most parts of climate change will continue for many millennia.
Alarming research suggests that crucial tipping points that could have resulted in permanent changes to the planet's climate system and major ecosystems have already been achieved or passed. Ecosystems as different as the Arctic tundra and the Amazon rainforest may be on the verge of significant change due to warming and dryness. Mountain glaciers are receding alarmingly, and the long-term implications of decreasing water availability during the driest months will be felt for many generations.
The IPCC issued a special report on the impacts of global warming of 1.5°C in October 2018
According to the IPCC's special assessment on the effects of global warming of 1.5°C, which was published in October 2018, limiting global warming to 1.5°C will necessitate swift, extensive, and unheard-of reforms in every sphere of civilization. The analysis discovered that limiting global warming to 1.5°C as opposed to 2°C may go hand in hand with guaranteeing a more sustainable and equitable society, with clear advantages to people and natural ecosystems. This paper reveals that many of the negative effects of climate change will occur at 1.5°C, as opposed to earlier predictions that concentrated on estimating the damage in the event that average temperatures rose by 2°C.
The paper also lists certain effects of climate change that may be avoided if global warming was kept to 1.5°C rather than 2°C or greater. For instance, 1.5°C of global warming would result in a 10 cm lower global sea level rise by 2100 than 2°C. With global warming of 1.5°C, the possibility of an Arctic Ocean free of sea ice in the summer would be once per century, as opposed to at least once every ten years with 2°C. With global warming of 1.5°C, coral reefs would experience a reduction of 70–90%, whereas with 2°C, practically all coral reefs will be gone.
According to the research, "rapid and far-reaching" changes in land, energy, industry, buildings, construction, transportation, and cities are necessary to keep global warming to 1.5°C. In order to attain "net zero" around 2050, global net human-caused carbon dioxide (CO2) emissions would need to decline by roughly 45 percent from 2010 levels by 2030. This implies that any residual emissions would require the removal of CO2 from the atmosphere in order to be balanced.
United Nations Framework Convention on Climate Change
The UN family is leading the charge to protect our planet. As a first step in tackling the climate change issue, its "Earth Summit" in 1992 resulted in the United Nations Framework Convention on Climate Change (UNFCCC). Nowadays, almost everyone can join. Parties to the Convention are the 197 nations that have ratified it. Preventing "dangerous" human intervention with the climate system is the Convention's ultimate goal.
Countries began negotiating in 1995 to improve the global response to climate change, and the Kyoto Protocol was adopted two years later. The Kyoto Protocol imposes strict legal obligations on developed country Parties to reduce their emissions. The Protocol's initial commitment period was from 2008 to 2012. From 2013 until 2020, the second commitment period was in effect. There are currently 192 Parties to the Kyoto Protocol and 197 Parties to the Convention.
Parties to the UNFCCC reached a historic agreement at the 21st Conference of the Parties in Paris in 2015 to battle climate change and to quicken and intensify the actions and investments required for a sustainable low-carbon future. The Paris Agreement builds on the Kyoto Protocol and, for the first time, unites all countries in the fight against climate change and adaptation to its effects, with increased support for helping developing nations do so. As a result, it plots a new course for the campaign to combat global warming.
The main objective of the Paris Agreement is to enhance the international response to the threat posed by climate change by limiting the rise in global temperature this century to well below 2 degrees Celsius and pursuing measures to further restrict the temperature increase to 1.5 degrees Celsius.
175 international leaders signed the Paris Agreement on April 22, 2016, Earth Day, at the UN headquarters in New York. This was by far the greatest number of nations to ever sign a treaty on a single day. The Paris Agreement has been ratified by 191 nations as of today.
2019 Climate Action Summit
To support the multilateral process and raise and accelerate climate action and ambition, Secretary-General António Guterres called a Climate Summit on September 23, 2019, in New York City. The summit brought together leaders of governments, the private sector, and civil society from around the world. He designated former Mexican diplomat Luis Alfonso de Alba as his Special Envoy to oversee the preparations. Heavy industry, nature-based solutions, cities, energy, resilience, and climate finance were among the major areas where the Summit put the most emphasis on which sectors may benefit most from action.
Global leaders discussed their current initiatives and future plans for action when they meet in 2020 for the UN climate conference, where commitments will be renewed and possibly increased. "You have delivered a lift in momentum, cooperation, and ambition," the Secretary-General remarked in his remarks at the summit's conclusion. However, we still have a ways to go.
"We require more detailed strategies, greater ambition from more nations and corporations. All public and private financial organizations must definitively select the green economy.
Al Gore, a former vice president of the United States, and the IPCC shared the 2007 Nobel Peace Prize in recognition of their collaborative work "to increase and spread information about man-made climate change, and to set the groundwork for the measures that are needed to mitigate such change."