Climate change became a real world issue in the mid-20th century when scientific evidence confirmed human activity, particularly fossil fuel use, as the primary driver of global warming.
Key moments include the historic CO₂ measurements in the 1950s and initiation of climate models in the 1960s. Political recognition, though started in late 1960s and saw international growth in 1970s, resulted in global agreements concerned with emissions, though a bit late, like the 1997’s Kyoto Protocol and the 2015 Paris Agreement.
Intergovernmental Panel on Climate Change (IPCC) established in 1988 and United Nations Framework Convention on Climate Change (UNFCCC) adopted in 1992 laid the foundation for global efforts to assess, address, and coordinate action on climate change through scientific research, policy guidance, and international agreements.
We can conclude that systematic studies concerning the alterations in global climate patterns began in the 1970s, and by the 1980s, the connection between human activities and climate change was firmly established.
Public awareness and international action since the 1970s made climate change a central environmental issue.
Earth’s climate has changed multiple times throughout history. Over the last 800,000 years, there have been accounts of eight cycles of ice ages and warmer periods. The last ice age ended around 11,700 years ago. This marked the beginning of modern human civilization.
Climate change is happening fast. The signs and evidence are clear. Global temperatures and sea levels are rising. Oceans are warming. Ice sheets and glaciers are shrinking. Arctic sea ice is melting. Extreme weather is becoming more frequent. Oceans are getting more acidic. All of this points to human-driven changes in Earth’s climate.
Recent global warming is happening at an unprecedented rate, and it is mainly due to human activities.
A systematic scientific study of climate change began in the 1970s when scientists started studying historic data from natural sources like ice cores, rocks, and tree rings.
Modern equipment like satellites and other instruments have become instrumental in climate modeling. This led to data and statistics showing that the recent warming rates of the Earth’s system are higher than any seen in the last 10,000 years.
A University of Arizona study shows that rising greenhouse gases and melting ice sheets have been the main causes of climate change since the last ice age. It found a warming trend over the past 10,000 years, but the pace and scale of warming in the last 150 years is far greater than at any time in the past 24,000 years.
Current warming is alarming with world-vulnerable communities facing severe environmental consequences. This rise in global average temperature is largely driven by human activities since the mid-1800s when industrialization, fossil fuel use, and human population started rising at an unprecedented rate.
Human actions since have released a great volume of gases into the atmosphere. This led to far greater trapping of the Sun’s energy, warming the Earth’s land, air, and oceans.
This rise in heat energy due to emissions started affecting the biosphere, atmosphere, oceans, and ice regions.
“Since systematic scientific assessments began in the 1970s, the influence of human activity on the warming of the climate system has evolved from theory to established fact.”
Intergovernmental Panel on Climate Change (IPCC)
The heat-trapping nature of carbon dioxide and other greenhouse gases has been known since the mid-19th century. Ice cores from Greenland and Antarctica, along with ocean sediments, coral reefs, and tree rings, show evidence of the climate change the world has experienced since the Industrial Revolution.
Evidence shows CO₂ levels in the atmosphere have risen about 250 times faster than natural processes after the last ice age.
Climate change awareness has grown over time.
Early awareness emerged in the 19th century. A strong global response developed by the 21st century. Understanding its history helps us see how far science has come regarding the issue of climate change.
Early scientific theories about human-caused climate impacts began in the 1800s. However, it wasn’t until the 1950s and 1960s that scientists started to describe that human activity was responsible for warming the Earth.
Detailed CO₂ measurements in the 1950s and advanced climate models from the 1960s onward have since revealed the true scale of human-driven changes.
“Scientific evidence for warming of the climate system is unequivocal.”
Intergovernmental Panel on Climate Change (IPCC)
1800s to Early 1900s: The Climate Change Science Begins
In the early 1800s, different scientists began studying and understanding the relationship between carbon dioxide (CO₂) and Earth’s temperature.
In 1824, French scientist Joseph Fourier suggested that Earth’s atmosphere might trap heat. This concept is now known as the “greenhouse effect.”
In 1895, Swedish scientist Svante Arrhenius proposed that burning fossil fuels like coal could raise atmospheric carbon dioxide (CO₂) levels and increase global temperatures.
The origin of the term greenhouse effect is uncertain. While Joseph Fourier noted in 1824 that Earth’s atmosphere acts like an insulating “hotbox,” it was Swedish scientist Svante Arrhenius in 1896 who first linked atmospheric gases to heat retention.
Arrhenius studied how CO₂ levels affect Earth’s temperature. He found that if CO₂ was halved, temperatures could drop by about 5°C (9°F). Then he tested if doubling CO₂ would raise temperatures by the same amount, which it would.
Today’s climate models have confirmed that Arrhenius’ predictions were close. They certainly confirmed their heating effects on the natural climate. While his research didn’t alarm people at the time, it laid the groundwork for understanding the effects of greenhouse gases on average global temperatures.
As Arrhenius wrote,
“By the influence of the increasing percentage of carbonic acid [CO2] in the atmosphere, we may hope to enjoy ages with more equable and better climates, especially as regards the colder regions of the earth.”
1900s: New Discoveries, Growing Concern
In the 1930s, British engineer Guy Stewart Callendar suggested that carbon emissions might already be causing a warming effect on Earth’s system.
He observed significant warming in the United States and the North Atlantic since the Industrial Revolution. He was arguably the first scientist to discover the connection between human activities and global warming.
Callendar predicted that global temperatures would increase by 0.39 degrees Celsius by the 21st century. Global temperatures have risen by three times that degree.
He continued arguing into the 1960s that greenhouse effect warming was indeed a real phenomenon. His claims certainly brought the world’s attention to global warming. Climate change has begun to become a reality and not just a myth.
In the 1950s, with the help of the latest technology, scientists began taking more accurate measurements of CO₂. With the Industrial Revolution fossil fuel use had massively surged leading to higher CO₂ emissions in the atmosphere.
The human population was on a rapid rise due to industrialization. More industries, factories, and energy production meant more emissions.
During the 1950s, U.S. scientist Charles David Keeling developed a method to measure atmospheric CO₂.
In 1958, the Scripps Institution of Oceanography set up the CO₂ monitoring station atop Hawaii’s Mauna Loa Observatory. Charles Keeling led the station. Data from this station introduced the “Keeling Curve,” which showed a clear rise in CO₂ levels over time with seasonal fluctuations.
Climate computer models began predicting that a doubling of CO₂ could lead to a 2°C (3.6°F) temperature rise within a century. Although the models were still in their early stages, the evidence was there. The data showed a steady increase in CO₂ that supported Arrhenius’s theory.
Also Read: Understanding the Basics of Carbon Footprint: What It Is and Why It Matters
So by the 1960s, scientists started to connect the dots, linking human activities with potential changes in Earth’s climate.
In 1965, a U.S. presidential advisory committee reported on the potential dangers of CO₂ emissions.
January 13, 1965, Memorandum For The President
“The Task Force on Environmental Pollution, which did such an outstanding job . . . is continuing, as a Panel to consider a series of questions related to Environmental Pollution. The topics presently under consideration include:
. . . The effects of carbon-dioxide on climate.”
source: Worth
This marks one of the earliest political recognitions of carbon dioxide effect on climate change.
1970s-1990s: Public Awareness and Environmental Activism
The 1970s marked a shift, as climate concerns began entering public discourse. During the 1970s, environmental issues like pollution and nuclear energy came into the public spotlight. Discussions and public concerns about climate change began to increase.
By the 1980s, evidence of climate change effects became harder to ignore.
In 1988, the United Nations created the Intergovernmental Panel on Climate Change (IPCC). The global body assesses scientific data on climate change and provides policy guidance.
“The Intergovernmental Panel on Climate Change (IPCC) was established in 1988 to provide policymakers with regular scientific assessments on the current state of knowledge about climate change.”
The IPCC’s first report in 1990 confirmed that CO₂ and other greenhouse gases were warming the planet.
In 1988, global warming gained serious attention with record-high summer temperatures, drought, and wildfires in the U.S. NASA scientist James Hansen testified to Congress, stating he was “99 percent sure” of global warming.
In 1992, over 150 countries signed the United Nations Framework Convention on Climate Change (UNFCCC). This was a first in committing to limit greenhouse gas emissions by world nations.
IPCC predictions included severe heat waves, stronger hurricanes, and rising sea levels by up to many inches by 2100. Therefore, in 1997, the Kyoto Protocol became the first global agreement to reduce greenhouse gas emissions.
However, due to a complex ratification process, it was not until 2005 that it entered into force.
2000s-Present: Accelerated Impacts and More Action
The early 2000s saw a rise in public awareness, fueled by extreme weather events and high-profile scientific reports.
Urgency and climate change effects became more visible in the 2000s, with extreme weather, melting glaciers, and rising sea levels.
It was 2006 when former Vice President Al Gore highlighted the dangers of global warming with his film An Inconvenient Truth. He won the 2007 Nobel Peace Prize for his climate change advocacy.
In 2015, the Paris Agreement brought countries together to limit global temperature rise to “well below” 2°C (with efforts to keep it under 1.5°C) compared to pre-industrial levels. Close to 200 countries are committed to reducing emissions, transitioning away from fossil fuel use, going renewable energy, combating pollution sources, and promoting sustainable practices and management of natural resources.
By 2021, the effects of climate change were being felt worldwide. The record-breaking heatwaves, hurricanes, and wildfires intensify calls for all sectors’ climate action. Environmental movements had started all over the world.
| Year | Event | Significance |
|---|---|---|
| 1824 | Joseph Fourier | First concept of atmospheric heat trapping. |
| 1895 | Svante Arrhenius | The early theory of the influence of carbonic acid (CO2) on warming Earth. |
| 1938 | Callendar observes CO₂ rise linked to warming. | The first link of human-caused global warming. |
| 1958 | Keeling Curve | Records of global atmospheric carbon dioxide concentration. |
| 1965 | U.S. report on CO₂ risks. | First government acknowledgment of CO2 effect on climate change. |
| 1988 | IPCC | UN body on regular scientific assessments on climate change. |
| 1992 | UNFCCC | To provide the basis for international climate negotiations. |
| 1997 | Kyoto Protocol | First binding emission reduction targets. |
| 2015 | Paris Agreement 2015 | Global pact to limit warming to below 2°C. |
Current Trends in Climate Change
According to the 2023 IPCC report, to limit global warming to 1.5 degrees Celsius, GHG emissions must peak before 2025 and decrease by 43% by 2030. Current national climate pledges would only reduce emissions by 7% by 2030, significantly missing the target.
“CO2 concentrations have increased 11.4 % in just 20 years.”
World Meteorological Organization (WMO)
Today, climate change is central in political, economic, and social discussions. Global CO₂ levels have risen massively due to fossil fuel combustion. The recent data shows an average global temperature increase of at least 1.1°C (1.9° Fahrenheit) since 1880.
Also Read: UNEP’s Emissions Gap Report 2024 – No more hot air … please!
The 2015 Paris Climate Agreement saw 197 countries commit to setting their greenhouse gas reduction targets and tracking progress. A key goal was to keep global temperature rise under 2°C (3.6°F) and pursue to limit the rise to 1.5°C above the pre-industrial levels.
If the target is not met, experts predict severe impacts like deadly heat waves, droughts, storms, and rising sea levels.
Year 2016 and 2020 tied, NASA and NOAA confirmed the years as the hottest since records began in 1880. 2023 became the hottest year on record next with 2024 predicted to become the latest hottest year on record.
In 2018, Swedish teenager Greta Thunberg began protesting about climate action by organizing school walkouts. She sparked a global climate strike movement and founded the Youth Strike for Climate movement.
Nominated for a Nobel Peace Prize in 2019, Thunberg attended the UN Climate Summit by boat, advocating for low-carbon travel. At the UN, she condemned leaders for neglecting climate action, saying,
“We are in the beginning of a mass extinction, and all you can talk about is money and fairy tales of eternal economic growth. How dare you.”
| Climate Change Indicator | Description |
|---|---|
| Global Temperature Rise | Earth’s temperature has risen by an average of 0.11° Fahrenheit (0.06° Celsius) per decade since 1850, or about 2° F in total. |
| Warming Oceans | The ocean’s top 100 meters have warmed by 0.67°F (0.33°C) since 1969. Earth stores 90% of the extra energy in the ocean. |
| Shrinking Ice Sheets | Greenland lost 279 billion tons of ice per year, and Antarctica 148 billion tons, from 1993 to 2019. |
| Retreating Glaciers | Glaciers are receding worldwide, including in the Alps, Himalayas, and Rockies. |
| Decreasing Snow Cover | Northern Hemisphere spring snow cover has decreased over the past five decades, with snow melting earlier. |
| Rising Sea Levels | Global average sea level has risen 8-9 inches since 1880, |
| Declining Arctic Sea Ice | Arctic sea ice has decreased in both thickness and extent over recent decades. |
| More Extreme Events | Record high temperatures and intense rainfall events in the U.S. have increased since 1950. The number of record low temperature events has been decreasing, since 1950. |
| Increasing Ocean Acidification | Ocean acidification has increased rapidly causing pH to drop by approximately 30% since the pre-industrial era, as it absorbs 20-30% of CO₂ emissions. |
Conclusion
Climate change evolved from a scientific theory in the 19th century to one of the most pressing global issues today.
Decades of research and international agreements underscore the critical need to limit emissions and adapt to a changing world.
Climate change became a widely recognized issue through scientific study, public awareness, and international action.
From early CO₂ discoveries to the Paris Agreement, it’s clear that addressing climate change is now a global priority.
While progress has been made, the challenge is urgent. Therefore, further action is critical to mitigate and adapt to the most severe impacts of climate change.
