Are humans responsible for climate change?

Yes. The overwhelming scientific consensus is that humans are responsible for climate change.

The evidence:

•The IPCC's Synthesis Report (March 2023) published by a UN organization including 195 member countries and thousands of independent scientific experts, concluded that human activities, principally through greenhouse gas emissions, have unequivocally caused global warming.

•It is "extremely likely," with 95-100% certainty, that human activity, as opposed to naturally occurring phenomena, has been the primary cause of climate change, according to earlier IPCC assessments.

•The scientific consensus itself is remarkably strong. Multiple independent studies have found that between 90 and 100 per cent of scientists agree that humans are responsible for climate change, with most of the studies finding a 97 per cent consensus. A 2021 study found a greater than 99 per cent consensus on human-induced climate change in the peer-reviewed scientific literature, a level of certainty similar to that of the theory of evolution.

•Major scientific organizations worldwide back this up. For example, the American Geophysical Union states it is extremely likely that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming since the mid-20th century.

The mechanism: Human activities are causing climate change, primarily due to the burning of fossil fuels like coal, oil, and gas. Burning fossil fuels creates a blanket of pollution trapping the sun's heat on Earth and raising global temperatures.

What this means practically: Humankind is the main driver behind the increase in average temperatures, heat waves, heavy rainfall, droughts and tropical cyclones, as well as the decrease in Arctic sea ice and the reduction of snow cover and permafrost. Notably, the IPCC has drawn attention to the role of methane in climate change, declaring that this gas—mainly produced in livestock farming—is responsible for around 30% of global warming since the pre-industrial era.

While natural factors (like volcanic activity and solar variation) have influenced climate in the past, over the last 200 years, these natural causes have not significantly affected global temperatures compared to human-driven greenhouse gas emissions. This conclusion is supported by multiple independent lines of evidence—including atmospheric measurements, ocean heat content, and ice-core records—making it one of the most robustly supported findings in modern science.

Citations (9)

1caltech.eduAcademic
What Is the Evidence that Human-Caused Climate Change is Happening? - Caltech Science Exchange
Source excerpt: “### The role of human activity The Intergovernmental Panel on Climate Change (IPCC), a United Nations organization that includes 195 member countries ...”
2iisd.orgNonprofits and think tanks
IPCC Report Finds Warming Unequivocal, Human Influence Dominant Cause
Source excerpt: “More specifically, it describes it is “extremely likely,” with 95-100% certainty, that human activity, as opposed to naturally occurring phenomena, ha...”
3un.orgGovernment
Myth Busters
Source excerpt: “Multiple independent studies have found that between 90 and 100 per cent of scientists agree that humans are responsible for climate change, with most...”
4un.orgGovernment
Myth Busters
Source excerpt: “A 2021 study found a greater than 99 per cent consensus on human-induced climate change in the peer-reviewed scientific literature (reviewed by expert...”
5nasa.govGovernment
scientific consensus
Source excerpt: “(2016-2019)4 • AGU emblem American Geophysical Union "Based on extensive scientific evidence, it is extremely likely that human activities...”
6un.orgGovernment
Myth Busters
Source excerpt: “Today, it’s human activities that are causing climate change, primarily due to the burning of fossil fuels like coal, oil, and gas. (IPCC) Burning fo...”
7activesustainability.comNot yet classified
Confirmed by the IPCC: we are to blame for climate change
Source excerpt: “Humankind is the main driver behind the increase in average temperatures, heat waves, heavy rainfall, droughts and tropical cyclones, as well as the d...”
8activesustainability.comNot yet classified
Confirmed by the IPCC: we are to blame for climate change
Source excerpt: “Moreover, for the first time, the IPCC has drawn attention to the role of **methane** in climate change and declared that this gas—mainly produced in ...”
9un.orgGovernment
Myth Busters
Source excerpt: “# Myth Busters ## FACT: Climate change is caused by human activity Natural changes in the sun’s activity or large volcanic eruptions have caused ancie...”