Climate change, often referring to global warming, signifies the ongoing rise in Earth's average temperature and its impact on the climate system. This increase, primarily driven by human activities since the Industrial Revolution, stems from burning fossil fuels, deforestation, and certain agricultural and industrial practices. These actions release greenhouse gases, such as carbon dioxide, which trap heat from the sun and warm the planet. The current levels of carbon dioxide are unprecedented in millions of years, emphasizing the significant human influence on climate change.
1900: Pre-industrial Baseline End
The period of 1850–1900 is commonly used as the pre-industrial baseline for measuring temperature changes.
1938: Guy Stewart Callendar's Evidence for Warming
Guy Stewart Callendar began publishing evidence in 1938 that the climate was warming and CO2 levels were rising. However, his findings faced resistance and skepticism from some scientists who believed in other climate mechanisms.
1961: Beginning of Global Dimming Observations
From 1961, scientists began to observe a gradual decrease in the amount of sunlight hitting the Earth's surface, a phenomenon later termed "global dimming."
1970: Shift in Temperature Trends
Between the 18th century and 1970, there was minimal net warming due to the cooling effects of sulfur dioxide emissions offsetting greenhouse gas warming. After 1970, a significant temperature increase occurred due to the buildup of greenhouse gases and the control of sulfur pollution.
1970: Ocean Heat Accumulation
Since at least 1970, there has been a continuous increase in the thermal energy within the global climate system, with over 90% of the extra energy being stored in the ocean.
1975: First Use of "Global Warming"
The term "global warming" emerged as early as 1975.
1980: Increase in Monsoonal Precipitation in the Northern Hemisphere
Since 1980, there has been a noticeable increase in monsoonal precipitation over the Northern Hemisphere.
1981: Start of Study Period for Climate Change Impact on Crop Yields
Research revealed that between 1981 and 2010, climate change negatively affected global yields of major crops like maize, wheat, and soybeans.
1987: Montreal Protocol Addresses Ozone Depletion
The 1987 Montreal Protocol, an international treaty designed to phase out ozone-depleting substances, has unexpectedly been more effective in curbing greenhouse gas emissions than the Kyoto Protocol, which was specifically created for that purpose.
1988: James Hansen's Congressional Testimony and IPCC Formation
In 1988, James Hansen's impactful testimony before Congress highlighted the dangers of climate change. The same year saw the establishment of the Intergovernmental Panel on Climate Change (IPCC), an international body formed to provide governments with scientific advice on climate change.
1988: Hansen's Testimony
In 1988, NASA climate scientist James Hansen popularized the term "global warming" during his testimony in the U.S. Senate.
1990: End of Global Dimming Trend
By 1990, the global dimming trend started to reverse due to pollution control measures, leading to less masking of the warming effects of greenhouse gases.
1990: Underestimation of Sea Level Rise in Early Models
Climate models from before 1990 underestimated the rate of sea-level rise observed since then, highlighting the evolving understanding of climate processes.
1993: Start of Detailed Global Sea Level Rise Monitoring
Between 1993 and 2020, meticulous monitoring revealed a concerning trend of accelerating global sea level rise.
1994: United Nations Framework Convention on Climate Change (UNFCCC) Established
The UNFCCC, a landmark environmental treaty, was established in 1994 with the aim of stabilizing atmospheric greenhouse gas concentrations to prevent dangerous human interference with the climate system.
1997: Kyoto Protocol Extends UNFCCC
The Kyoto Protocol, adopted in 1997, built upon the UNFCCC by introducing legally binding emission reduction targets for most developed nations. This agreement acknowledged the historical responsibility of developed countries for greenhouse gas emissions.
1998: Beginning of "Global Warming Hiatus"
From 1998 to 2013, a "global warming hiatus" occurred, characterized by a slower rate of surface warming attributed to negative phases of the Pacific Decadal Oscillation (PDO) and Atlantic Multidecadal Oscillation (AMO).
2000: Long-term Sea Level Rise Projections
After 2000, projections estimated a long-term sea level rise of 2.3 meters per degree Celsius of warming, highlighting the lasting consequences of climate change on oceans.
2001: Deforestation and Land Use Change
Between 2001 and 2018, deforestation significantly contributed to global warming, releasing CO2 and reducing carbon sinks.
2004: The Day After Tomorrow Release
The release of the climate fiction movie "The Day After Tomorrow" in 2004 brought climate change into popular culture, though it often got confused with other environmental issues.
2006: An Inconvenient Truth Release
Al Gore's documentary "An Inconvenient Truth," released in 2006, focused on climate change and further increased public attention to the issue.
2009: Copenhagen Accord Sets Temperature Goal
The 2009 Copenhagen Accord, while facing criticism for its perceived lack of ambition, set a goal to limit global temperature rise to below 2°C.
2010: Agriculture and Forestry's Climate Challenge
The agriculture and forestry sectors face the threefold challenge of reducing greenhouse gas emissions, halting deforestation for agriculture, and meeting the growing global demand for food. Strategies to address these challenges aim to cut emissions by two-thirds from their 2010 levels.
2010: End of Study Period for Climate Change Impact on Crop Yields
The period between 1981 and 2010 provided crucial data, demonstrating the negative impact of climate change on global crop yields, raising concerns about future food security.
2010: Baseline for Emissions Reduction Goals
The year 2010 served as a baseline for measuring progress in reducing greenhouse gas emissions under the Paris Agreement and national climate plans. Countries aimed to achieve significant reductions in their emissions compared to their 2010 levels.
2013: Start of Recent Warming Period
The decade from 2013 to 2022 experienced significant warming, averaging 1.15 °C higher than the pre-industrial baseline.
2015: Paris Agreement
The Paris Agreement, a landmark international treaty, was adopted in 2015 with the goal of limiting global warming to well below 2 °C above pre-industrial levels.
2015: Paris Agreement Unites Nations on Climate Action
The landmark Paris Agreement, adopted in 2015, brought together all UN member states in a commitment to combat climate change. It set a goal to limit global warming to well below 2°C, with aspirations to keep it under 1.5°C, replacing the Kyoto Protocol.
2016: World Bank Report on Climate Change and Poverty
The World Bank, in 2016, estimated that without appropriate adaptation measures, climate change could force over 120 million people into extreme poverty between 2016 and 2030, highlighting the intersection of climate change and socioeconomic vulnerability.
2016: Kigali Amendment Strengthens Montreal Protocol
The Kigali Amendment, added to the Montreal Protocol in 2016, targets hydrofluorocarbons (HFCs), potent greenhouse gases often used to replace banned ozone-depleting substances. This amendment significantly strengthens the Montreal Protocol's role in mitigating climate change.
2016: Air Pollution Deaths Reach 7 Million
Air pollution, linked to fossil fuel use, caused an estimated 7 million deaths globally in 2016, highlighting the severe health impacts of climate change.
2017: Fossil Fuel Subsidies Remain High
In 2017, global fossil fuel subsidies amounted to $319 billion in direct funding and a staggering $5.2 trillion when considering indirect costs like air pollution.
2017: Publication of the United States National Climate Assessment
The United States-published National Climate Assessment in 2017 pointed out that existing climate models may still underestimate or miss certain climate feedback processes, indicating ongoing refinements needed in modeling.
2018: Deforestation and Land Use Change
Between 2001 and 2018, deforestation significantly contributed to global warming, releasing CO2 and reducing carbon sinks.
2018: School Strike for Climate Begins
Inspired by Greta Thunberg, the School Strike for Climate movement began in 2018. Young people worldwide skipped school on Fridays to demand action on climate change.
2018: Remaining Carbon Budget
To limit global warming to 1.5 °C with a two-thirds chance, emissions after 2018 cannot exceed 420 or 570 gigatonnes of CO2, equivalent to 10 to 13 years of current emissions. This highlights the urgency of reducing emissions and transitioning away from fossil fuels.
2019: Climate Emergency Declarations Gain Momentum
The United Kingdom made history in 2019 by becoming the first national government to declare a climate emergency. Subsequently, other countries and jurisdictions followed suit, with the European Parliament issuing a similar declaration.
2019: Global Greenhouse Gas Emissions
In 2019, global anthropogenic greenhouse gas emissions reached 59 billion tonnes of CO2 equivalent. CO2 emissions mainly originated from fossil fuel burning for energy, while methane emissions came from livestock, agriculture, and fossil fuel extraction.
2019: Scientific Consensus on Human-Caused Climate Change Solidifies
By 2019, the scientific consensus on climate change reached over 99%, with no major scientific body disputing the role of human activities in global warming.
2019: Renewable Energy Dominates New Power Generation
In 2019, a significant shift occurred in electricity generation, with renewables accounting for 75% of all new installations, mainly solar and wind power.
2019: Greenhouse Gas Concentrations Reach Record Highs
By 2019, CO2 and methane concentrations had surged by approximately 48% and 160%, respectively, compared to levels in 1750, reaching unprecedented levels in the past 2 million and 800,000 years.
2019: Carbon Pricing Coverage Expands
By 2019, carbon pricing mechanisms, such as carbon taxes and emissions trading systems, covered approximately 20% of global greenhouse gas emissions.
2020: Impact of Reduced Sulfur Content in Fuel Oil
Since 2020, decreasing the sulfur content in fuel oil for ships, while beneficial in reducing air pollution, is estimated to contribute to a slight increase in global temperature (0.05 °C) by 2050.
2020: Green Climate Fund Funding Shortfall
The Green Climate Fund, proposed in the Copenhagen Accord, aimed to provide $100 billion annually by 2020 to developing countries for climate change mitigation and adaptation. However, the fund fell short of this target.
2020: End of Detailed Global Sea Level Rise Monitoring Period
The period between 1993 and 2020 marked a significant period of monitoring global sea level rise, providing crucial data for understanding the impact of climate change on oceans.
October 2021: Widespread Adoption of Paris Agreement
By October 2021, the Paris Agreement had garnered widespread support, with 194 states and the European Union signing the treaty and 191 states and the EU ratifying or acceding to it.
October 2021: UNEP Assessment of Paris Agreement Pledges
In October 2021, the United Nations Environment Programme (UNEP) assessed the pledges made by countries under the Paris Agreement, revealing a potential warming of about 2.7°C by the century's end, even with those commitments.
2021: Growing Global Concern for Climate Change
By 2021, a majority of citizens in many countries expressed a high level of worry about climate change, with many considering it a global emergency. This increased concern led to stronger public support for policies addressing climate change.
2021: National Climate Plans and Emissions Gap
In 2021, an assessment of 48 national climate plans, representing 40% of the parties to the Paris Agreement, revealed that estimated total greenhouse gas emissions would be only 0.5% lower than 2010 levels. This fell significantly short of the 45% or 25% reduction goals set to limit global warming to 1.5 °C or 2 °C, respectively.
2021: European Union Proposes "Fit for 55" Legislation
The European Commission introduced its "Fit for 55" legislative package in 2021, outlining a roadmap for various sectors, including the automotive industry. A key provision mandates that all new cars sold in the EU must be zero-emission vehicles starting in 2035.
2021: IPCC Confirms Unequivocal Human Influence on Climate Change
The IPCC's 2021 assessment report unequivocally stated that human activities are the primary driver of climate change, further solidifying the scientific consensus.
2022: End of Recent Warming Period
The decade from 2013 to 2022 experienced significant warming, averaging 1.15 °C higher than the pre-industrial baseline.
2023: Potential for Exceeding 1.5 °C Warming
The World Meteorological Organization estimates a 66% chance that global temperatures will surpass 1.5 °C warming above pre-industrial levels for at least one year between 2023 and 2027.
2023: Green Climate Fund Funding Target Expected to Be Reached
The $100 billion annual funding target for the Green Climate Fund, initially set for 2020, is anticipated to be finally achieved in 2023.
2023: High Temperature Anomalies
Years like 2023 have shown temperatures notably above the recent average, highlighting the influence of natural climate variability on annual temperatures.
2023: IPCC Sixth Assessment Report Projections
The IPCC's Sixth Assessment Report, released in 2023, projects that by 2100, global warming is likely to reach 1.0-1.8 °C under a low-emission scenario, 2.1-3.5 °C under an intermediate-emission scenario, and 3.3-5.7 °C under a very high-emission scenario.
2023: Wealth Disparity in Emissions Responsibility
A 2023 Oxfam report revealed a stark disparity in emissions responsibility, with the wealthiest 10% of the global population accounting for 50% of emissions, while the poorest 50% were responsible for a mere 8%.
2023: Warmest Year on Record
In 2023, the global temperature was the warmest ever recorded since tracking began in 1850, reaching +1.48 °C (2.66 °F) above pre-industrial levels.
2025: Fossil Fuel Companies' Potential Climate Debt
Based on their contribution to emissions, the top 21 fossil fuel companies could potentially owe a cumulative $5.4 trillion in climate reparations between 2025 and 2050.
2027: Potential for Exceeding 1.5 °C Warming
The World Meteorological Organization estimates a 66% chance that global temperatures will surpass 1.5 °C warming above pre-industrial levels for at least one year between 2023 and 2027.
2030: Projected Peak of Fossil Fuel Use
Fossil fuel consumption is expected to peak in 2030 before beginning its decline, with coal experiencing the sharpest drop.
2030: WHO Projection on Additional Deaths Due to Climate Change
The WHO estimated that between 2030 and 2050, climate change would contribute to approximately 250,000 additional deaths annually, underscoring the severe health threats posed by a changing climate.
2030: End of Projection Period for World Bank Report on Climate Change and Poverty
The World Bank's projection period, from 2016 to 2030, served as a critical timeframe for understanding the potential socioeconomic consequences of climate change, particularly the risk of increasing poverty.
2030: Emissions Reduction Target
To limit global warming to 1.5 °C, global emissions need to be halved by 2030.
2035: Zero-Emission Vehicle Mandate in the EU
Starting in 2035, all new cars entering the European market must be zero-emission vehicles, as per the guidelines set forth in the EU's "Fit for 55" legislation.
2050: End of WHO Projection Period for Additional Deaths Due to Climate Change
The WHO's projection of 250,000 additional deaths per year due to climate change, spanning from 2030 to 2050, highlights the urgent need for mitigation and adaptation strategies.
2050: Target for Net-Zero Greenhouse Gas Emissions
To limit global warming to 1.5 °C, a goal set by international agreements, global greenhouse gas emissions need to reach net-zero by 2050, underscoring the urgency for immediate and drastic climate action.
2050: Renewable Energy's Projected Dominance
To achieve carbon neutrality by 2050, renewable energy sources are projected to become the primary source of electricity, reaching 85% or more in some scenarios. This shift aims to phase out coal use almost entirely by the same year.
2050: End of Fossil Fuel Reparations Period
The period for potential climate reparations from fossil fuel companies, as suggested, would extend until 2050.
2050: Net-Zero Emissions Target
Achieving net-zero emissions by 2050 is necessary to limit global warming to 1.5 °C.
2050: European Union Aims for Carbon Neutrality
The European Commission unveiled its European Green Deal in 2019, setting an ambitious target for the EU to achieve carbon neutrality by 2050.
2050: Carbon Neutrality Pledges in Asia
South Korea and Japan have committed to reaching carbon neutrality by 2050, aligning with global efforts to combat climate change.
2050: Potential Impact of Limiting Black Carbon in the Arctic
Projections indicate that limiting new black carbon deposits in the Arctic by 2050 could potentially reduce global warming by 0.2 °C.
2050: Potential Lives Saved by Limiting Warming
Achieving the Paris Agreement's goal of limiting global warming to 2°C could prevent approximately one million air pollution-related deaths per year by 2050.
2060: China's Carbon Neutrality Goal
China, a major global player, has pledged to achieve carbon neutrality by 2060 as part of its commitment to addressing climate change.
2070: Alternative Target for Net-Zero Greenhouse Gas Emissions
If the target is a 2°C increase, net-zero emissions need to be achieved by 2070, highlighting the impact of different warming limits on the timeline for climate action.