This Hub is a cross-campus effort of the Precourt Institute for Energy. Take the Understand Energy course for credit.

Energy and Climate Change

Fast Facts About
Climate Change

Printable PDF, 751KB

Energy use is the leading cause of climate change, accounting for over 75% of anthropogenic (human-caused) greenhouse gas (GHG) emissions. Rising GHG levels due to carbon-intensive human activities like fossil fuel combustion, land use, and agriculture since pre-industrial times have resulted in an increase in the Earth’s surface temperature, which is known as global warming. Though people tend to use the terms global warming and climate change interchangeably, global warming is just one aspect of climate change. Climate change includes global warming and other climate effects like melting glaciers, more frequent droughts, and increased severe weather events.

Some GHGs occur naturally in our atmosphere and are important for regulating the Earth’s temperature to support human and other forms of life in a process called the greenhouse effect. Sunlight hits the Earth, the Earth warms, and the Earth emits infrared radiation (heat). GHGs absorb some of the infrared radiation that would otherwise be released to space, further warming the Earth to a temperature that can support life. Naturally occurring GHGs like carbon dioxide and water vapor are part of the natural carbon cycle.

Increasing anthropogenic emissions of heat-trapping GHGs have thrown the natural carbon cycle out of balance, leading to increasing concentrations of GHGs in Earth’s atmosphere and causing climate change. The most impactful anthropogenic GHGs to date are carbon dioxide (CO2) and methane.

Climate change is an urgent problem for maintaining a livable planet for humans. We have a limited carbon budget (i.e., the maximum amount of CO2 and other GHGs we can emit into the atmosphere) before we exceed key climate tipping points. A global surface temperature increase of 1.5°C above pre-industrial levels is generally considered the threshold for preventing the most catastrophic climate impacts. Although the Paris Agreement includes a commitment to keep warming "well below 2°C," subsequent research by the Intergovernmental Panel on Climate Change (IPCC) indicated that the risks significantly increase at 2°C and emphasized the need to target 1.5°C. Every bit of extra warming beyond 1.5°C will cause increasingly severe impacts. The world is currently on track for about 3.1°C of warming in this century based on national policies.

We have scalable and cost-effective tools and solutions to tackle climate change, but implementation remains a huge challenge. Barriers include a lack of social will, a lack of robust government policies, and the vested interests of fossil fuel companies and fossil fuel exporting countries. Clean energy transitions are happening, but will they happen fast enough?

Tracking Climate Change

Average Global Surface Temperature Increase

1.3°C  / 2.34°F (2020-2024)
above pre-industrial levels (1850-1900)

2024 was the warmest year since global records began in 1850 and the second year above 1.5°C.

The 10 warmest years in the historical record have all occurred in the past decade (2015-2024).

Watch this 30-second NASA animation of global temperature anomalies from 1880 to 2024.

“It is unequivocal that human influence has warmed the atmosphere, ocean and land.”
— IPCC, 2023

Global Sources and Sinks of GHG Emissions

Key Impacts of Climate Change

There are numerous negative environmental impacts of climate change, many of which affect human health and morbidity. These include an increase in the number and duration of droughts, heatwaves, winter storms, and wildfires, as well as sea level rise, more frequent and more intense hurricanes, and biodiversity loss.

Global Mean Sea Level Rise

6 - 10 in / 15 - 25 cm
over the past 100 years

4.4 in / 11.3 cm
over the past 20 years

And the rate of global mean sea level rise is increasing:

  • 1.32mm/year (1901-1971)
  • 1.87mm/year (1971-2006)
  • 3.69mm/year (2006-2018)

Even these seemingly modest levels of increase can make coastal areas uninhabitable for humans and have been shown to cause greater flooding and worsen the impact of hurricanes.

Sea level rise occurs for two reasons: ocean water expands as it warms; and land-based glaciers and ice sheets are melting and adding more water to the oceans.

The Global Tipping Points 2025 report predicts we've already locked in long-term multi-meter sea level rise with the high risk of collapse of Greenland and West Antarctic ice sheets.

More Frequent and More Severe Wildfires

In California, land area burned due to wildfires increased by 320% between 1996 and 2021.

In Canada, the average area burned during a wildfire has doubled since 1970. The total area burned in the 2023 Canadian wildfire season, 45.5 million acres, was 6 times the 10 year average.

In Australia, an estimated 480 million animals died, including 15% of the koala population, in the 2019/2020 bushfires.

Additional wildfire impacts:

  • Air pollution - wildfire smoke contains harmful pollutants that cause cardiovascular and respiratory illness, asthma attacks, and premature death in humans
  • GHG emissions - wildfires release large quantities of carbon dioxide while burning, continue to release carbon dioxide as burned forests decompose, and reduce the land sink by destroying forests
  • Economic - the annual cost of wildfires in the US ranges from $394 billion to $893 billion, including costs from property damage, direct and indirect deaths and injuries, health impacts from wildfire smoke, income loss, and other factors

Ocean Acidification

Today’s surface ocean waters are 30% more acidic than pre-industrial ocean waters.

Ocean acidification is a result of CO2 dissolving in the ocean and forming carbonic acid.

The increased acidity can dissolve the calcium carbonate shells or skeletons of marine life like corals, clams, and mussels, which are often at the bottom of the food chain. This means that ocean acidification can impact many marine species.

Increased Risks of Extinction

About one-third of all plant and animal species are predicted to be at high risk of extinction by 2070 if climate change continues at its current rate.

Climate change increases the likelihood of extinction for over 14,000 threatened species.

Threats to Coral Reefs

Coral reefs are one of our most valuable ecosystems, providing habitat to at least 25% of the world’s marine life and playing a vital role in the food security of hundreds of millions of people worldwide. Coral reefs also protect our shorelines by serving as a natural barrier against waves, storms, and floods and are home to important filter feeders that filter toxins and contaminants out of the ocean water.

Climate change poses several serious threats to our coral reef ecosystems:

  • Rising ocean temperatures cause thermal stress, resulting in more frequent mass coral bleaching events and infectious disease outbreaks.
  • Sea level rise may lead to increases in sedimentation for reefs located near land-based sources of sediment, which can result in the smothering of coral.
  • Changes in storm patterns lead to stronger and more frequent storms that can cause coral reef destruction.
  • Precipitation changes resulting in increased runoff of freshwater, sediment, and land-based pollutants contribute to algal blooms and make water murky, reducing light.
  • Changes to ocean currents contribute to lack of food for corals and hinder the dispersal of coral larvae.
  • Ocean acidification (due to increased CO2) reduces pH levels, decreasing coral growth and structural integrity.

Visit our Decarbonize Your Life page for ways you can help reduce these impacts.
 

Cartoon illustration of the six threats to coral reefs from climate change outlined in the text above.
View larger

Climate Refugees from Natural Disasters

45.5 million
internal climate refugees* in 2024

69%
of all refugees are climate refugees

Natural disaster related displacements in 2024 was nearly 2x the annual average over the past 10 years.

Heat Related Deaths

37%
of heat related deaths are due to climate change

Heat wave frequency in the U.S. has increased from 2 per year in the 1960s to 6 per year in the 2010s and 2020s.

60,000 people died in Europe in 2022 due to extreme heat.

Flooding and Habitable Land Loss

11%
of the global population lives in low-lying coastal areas (<10 m above sea level), which are most susceptible to the impacts of a rising sea level

*Internal climate refugees are displaced within their country

Countries Particularly Vulnerable to Climate Change Impacts

Impacts of climate change are not equitably distributed. The countries that are or will be hardest hit by climate change are the ones that have contributed the least to it and have fewer resources to combat it.

Food Scarcity

Sub-saharan Africa, South Asia, Southeast Asia

Food scarcity can be caused by increased drought, water scarcity, and natural disasters.

Rising temperatures can also make growing crops more expensive, driving more people into poverty and food insecurity.

Wildfires

% of land area burned (2012-2024 average)

South Sudan 34% 🇸🇸
Sierra Leone 30% 🇸🇱
Angola 29% 🇦🇴
Zambia 28% 🇿🇲
Guinea 28% 🇬🇳
Central African Republic 27% 🇨🇫
Mozambique 23% 🇲🇿
Ghana 20% 🇬🇭

Geographies With Emerging Wildfire Risk

Siberia and the Arctic*, the Amazon (and other rainforests)

Sea Level Rise

Small island nations like Tuvalu, the Maldives, and the Marshall Islands are most at risk of impacts from sea level rise, including becoming uninhabitable.

These nations also have some of the smallest contributions to GHG emissions.

Heat Waves

Afghanistan, Central American nations like Guatemala, Honduras, Nicaragua

Their vulnerability includes not only their risk of heat waves, but also their inability to prepare and respond to them.

*Fires in these regions can melt permafrost, releasing significant amounts of trapped CO2 and methane into the atmosphere

Global Warming Potentials (GWP)

GWP is a measure of how much heat a GHG can trap in the atmosphere over specific time intervals, typically 20 and 100 years. GWP takes into account both the heat trapping ability of GHGs and their lifetime, which is the length of time they stay in the atmosphere.

 Lifetime (years)20 year GWP100 year GWP
Carbon Dioxide, CO2100-1,00011
Methane, CH4128127
Nitrous Oxide, N2O109273273
Hydrofluorocarbon, HFC-134a144,1441,526

Human-Caused GHG Emissions

GHG Emissions by Country

GHG emissions measurements by country can vary based on where/to whom emissions are assigned. For example, if a good is produced in China for a customer in the U.S., the emissions could be assigned to either country. Production-based measurements assign emissions to the producing country. Consumption-based emissions measurements are adjusted for trade and more accurately reflect the consumption and lifestyle choices of a country’s citizens. Most emissions data, including the data below, is presented as production-based. Consumption-based data is more difficult to calculate accurately.

Highest Annual GHG Emissions

China 32% 🇨🇳
U.S. 13% 🇺🇸
India 8% 🇮🇳
of global annual GHG emissions

Highest Per Capita GHG Emissions of Major Emitters (tCO2e*/person)

Australia 14.48 🇦🇺
U.S. 14.30 🇺🇸
Canada 13.98 🇨🇦

for comparison, China is at 8.39 and India is at 2.13
 

Highest Cumulative GHG Emissions

U.S. 24% 🇺🇸
EU 17% 🇪🇺
China 15% 🇨🇳
of cumulative GHG emissions
(1750-2023)

*tonnes of CO2 equivalent

U.S. GHG Emissions

Highest Annual GHG Emissions

Texas 14%
California 6%
of annual U.S. GHG emissions

Highest Cumulative GHG Emissions

Texas 12%
California 6%
Pennsylvania 4%
Ohio 4%
of cumulative U.S. GHG emissions
(1990-2022)

Factors Contributing to Lack of Social Will to Act on Climate Change in the U.S.

Lack of Belief

Only 59% of U.S. adults believe in human-caused climate change

Misinformation Campaigns From the Oil and Gas Industries

Millions of dollars have been spent on ads attacking renewable energy sources and promoting natural gas

As of 2022, more than 2 dozen U.S. cities, counties, and states are suing oil and gas companies over their role in the increasing hazards of climate change.

Climate Change Can Be Difficult to Understand and Communicate

Only 45% of U.S. adults believe global warming will harm them personally

Climate change has short term costs, but long term impacts.

How Do We Solve Climate Change?

Top 6 Cost-Effective Solutions to Climate Change by Mitigation Potential

Solar photovoltaics (PVs)
Wind energy
Energy efficiency and electrification in buildings
Reforestation
Decarbonized industrial processes
Vehicle electrification

Watch our Electrify Everything lecture to learn more about the benefits of electrification. 

How Companies and Organizations Categorize GHG Emissions

Scope 1, 2, and 3 emissions categories provide standardized ways for companies and organizations to account for and report their greenhouse gas emissions. The categories are based on the level of control that entities have over their emissions.

Scope 1

Direct emissions from sources controlled or owned by an organization

Includes emissions from:

  • Company vehicles
  • Fuel combustion
  • Fugitive emissions (from facility appliances or processes)

Scope 2

Indirect emissions associated with the purchase of electricity, steam, heat, or cooling; emissions do not physically occur at facilities owned or controlled by the reporting organization

Includes emissions from:

  • Electricity
  • Heat
  • Steam

Scope 3

Indirect emissions that an organization causes in its value chain (upstream and downstream of the organization’s activities); includes all emission sources not included in Scope 1 and 2

Includes emissions from:

  • Purchased goods and services
  • Business travel
  • Waste disposal
  • Transportation and distribution
  • Consumer's use of sold products

Solution Drivers

  • Cost-competitive solutions are ready to scale today
  • Policy support at international, national, and local levels (e.g., GHG reduction targets, clean electricity targets, carbon pricing mechanisms, building and vehicle electrification mandates)
  • Private sector engagement from large corporations, investors
  • Continued innovation and cost declines in hard-to-abate sectors (industry, air and ocean travel) and for engineered carbon capture technology

Solution Barriers

  • Need more ambitious policy from governments at all levels to accelerate scaling of solutions, including effective carbon pricing
  • Need more investment capital to accelerate scaling of solutions
  • Lack of social will:
    • Divergence between public opinion and the science (e.g, only 59% of U.S. adults believe in human-caused climate change)
    • Influence of incumbent fossil fuel interests
    • Competing priorities (energy prices and geopolitics)
    • Lack of international climate agreement
    • Lack of individual empowerment
Sources
 

Updated October 2025

Our 10-Minute Take On
Climate Change

If you're short on time, start by watching this video of key highlights from our lecture on Energy and Climate Change.

Diana Gragg

Presented by: Diana Gragg, PhD; Core Lecturer, Civil and Environmental Engineering, Stanford University; Explore Energy Managing Director, Precourt Institute for Energy
 

Recorded: October 3, 2025 
Duration: 13 minutes

Slides available upon request.

If you liked this video, watch the other 10-Minute Takes here!

Curated Videos and Readings on
Energy and Climate Change

We assign videos and readings to our Stanford students as pre-work for each lecture to help contextualize the lecture content. We strongly encourage you to review the readings and videos below before watching our lecture on Energy and Climate Change.

Our Lecture on
Energy and Climate Change

This is our Stanford University Understand Energy course lecture on climate change. We strongly encourage you to watch the full lecture to understand the significant role that energy plays in climate change and to be able to put this complex topic into context. For a complete learning experience, we also encourage you to watch / read the videos and readings we assign to our students before watching the lecture.

Kirsten Stasio

Presented by: Kirsten Stasio, Adjunct Lecturer, Civil and Environmental Engineering, Stanford University; CEO, Nevada Clean Energy Fund (NCEF)
Recorded on: April 4, 2025   Duration: 60 minutes

Table of Contents

(Clicking on a timestamp will take you to YouTube.)
00:00 Introduction 
04:43 What is the Science Behind Climate Change? 
19:29 How Do We Garner the Social Will to Act on Climate Change? 
33:26 How Do We Solve Climate Change?

Lecture slides available upon request.

Test Your Knowledge

Printable PDF: Questions, Answer Key

Additional Resources About
Climate Change

Stanford University Professors

Other Organizations and Resources

Next Topic: The Environment Other Energy Topics to Explore

Fast Facts Sources

More details available on request.
Back to Fast Facts