Greenhouse gas emissions from human activity accelerate recent global warming

Greenhouse gas emissions from human activities have contributed to global warming

A 2021 report from the Intergovernmental Panel on Climate Change found that such emissions were responsible for approximately 1.1 degrees Celsius (2.0 degrees Fahrenheit) of warming since 1850-1900. Without rapid, large-scale reductions in emissions, temperatures are expected to continue to rise, leading to more extreme weather events.

Carbon dioxide is the most produced greenhouse gas from human activities

In 2022, about 79.7% of US greenhouse gas emissions were carbon dioxide, produced through chemical reactions in processes such as cement production and the burning of fossil fuels, solid waste, trees, and other biological materials. Methane (11.1%), nitrous oxide (6.1%), fluorinated gases (3.1%), and trace amounts of solid and liquid aerosol were also created.

Excluding water vapor, greenhouse gases make up less than 1% of Earth's atmosphere

Although carbon dioxide, methane, nitrous oxide, ozone, and most fluorinated gases account for only a minority of the planet's greenhouse effect due to their lower concentrations, they are more effective at trapping thermal radiation. While water vapor condenses within two weeks, other greenhouse gases linger in the atmosphere for years on average.

Yearly greenhouse gas emissions have been steadily increasing since 1850

Although greenhouse gases include methane, nitrous oxide, and most fluorinated compounds, their warming potential is often measured relative to carbon dioxide. In these units, greenhouse gas emissions have gone from 4.29 billion metric tons of carbon dioxide equivalent in 1850 to 54.43 billion metric tons in 2024.

Nitrous oxide is the third most significant greenhouse gas made by human activities

Emissions of this molecule increased 40% from 1980 to 2020, with atmospheric concentrations reaching levels higher than at any other time in the last 800,000 years, based on ice core records. Its warming potential is 273 times that of carbon dioxide over 100 years and remains in the atmosphere for more than a century, on average.

Greenhouse gases from farming are driven by meat

The food we eat contributes to one-third of global greenhouse gas emissions caused by human activities, according to two studies published in 2021. These emissions come from various sources along the food production chain, including transportation,...

Fluorinated molecules are the most impactful, longest-lasting greenhouse gases

Developed as replacements for ozone-depleting substances in refrigeration and air conditioning systems, these compounds are released through leaks in and ongoing use of these appliances, as well as from various industrial processes. They can remain in the atmosphere for thousands of years and have warming potentials that are a thousand to tens of thousands of times greater than those of carbon dioxide.

Arctic permafrost may store twice as much carbon as the entire atmosphere

Rising greenhouse gas concentrations are expected to continue to increase average global temperatures and threaten to thaw ground that has been frozen for thousands of years. The release of greenhouse gases from remnant organic matter would exacerbate the greenhouse effect, creating a positive feedback loop.

How Earth's 'greenhouse effect' works

The so-called "greenhouse effect," where various gases in Earth's atmosphere trap heat from the sun, is a crucial factor in our planet's ability to sustain life. It's also pivotal in discussions over humanity's impact on changes in the Earth's...

Human activities release 100 times the carbon dioxide of all volcanic eruptions

While gases released by volcanoes contribute to climate change, humans produce the carbon dioxide equivalent of a Mount St. Helens-sized eruption every 2.5 hours, or more than one Yellowstone eruption yearly, even though such supervolcanoes only erupt about every 100,000 to 200,000 years or more.

Rapid environmental changes are exacerbating natural extinction processes

Human activities behind climate change, habitat destruction, pollution, and overhunting have resulted in extinction rates up to 1,000 times greater than normal, triggering massive biodiversity loss. This has led scientists to refer to the current geological age as the Anthropocene era, in which humans are the dominant force shaping nature.

Greenhouse gas removal consists of a series of techniques to capture and store GHGs

These include turning biomass into charcoal for storage in soil before it decays and releases carbon dioxide, crushing CO₂-absorbing rocks—increasing exposed surface area—and spreading them across land to accelerate GHG uptake, and restoring degraded peatlands, which can store twice the amount of carbon as the average forest.

How greenhouse gases and climate change impact the efficiency of photosynthesis

A review in the Journal of Experimental Botany found that higher temperatures reduce the efficiency of enzymes involved in photosynthesis and impair a plant's ability to control water loss and regulate carbon dioxide uptake. While increased carbon dioxide levels are understood to accelerate plant growth by boosting photosynthesis, researchers suggest these effects more than offset the potential gain.

Greenhouse gas concentrations can be measured using spectroscopy

Each type of greenhouse gas absorbs a distinct set of wavelengths of light, which serve as a unique spectral signature. By shining light through an atmospheric sample and measuring the light on the other side, the amount of each gas can be calculated from the amount of missing light.

Oceans absorb 90% of warming from greenhouse gases

Oceans are providing increasingly more energy to power hurricane intensity. Current projections show rapid intensification is becoming more common, increasing the likelihood of Category 4 and 5 storms.

Watch a demonstration of the greenhouse effect in carbon dioxide

Some online experiments involving glass containers of air and carbon dioxide show no temperature differences upon exposure to infrared light because glass blocks that type of radiation. Using plastic bags, carbon dioxide can be demonstrated to absorb infrared radiation, thereby trapping energy and confirming its role as a greenhouse gas.

View an illustrative guide to climate change for kids

While climates have changed throughout Earth's history, they are now changing faster than usual, driven by the burning of fossil fuels and the release of greenhouse gases, which trap more of the sun's radiation.

Global climate models simulate Earth system interactions and how human activity impacts climate

By splitting the planet into tiny 3D grid cells, supercomputers can run thousands of equations for each cell to determine the movement of energy, moisture, and other elements across Earth. The equations can also incorporate greenhouse gases to determine how humans affect the climate.

Carbon dioxide acts as a 'control knob' for Earth's climate

Although Earth's ice ages were primarily triggered by slow changes in the planet's orbit—known as Milankovitch cycles—these changes do not explain the extreme temperature swings during glacial periods. Carbon dioxide acts as a feedback mechanism, intensifying both cooling during ice ages and warming during their ends by reinforcing the initial changes sparked by orbital shifts.

Space tourism rockets emit up to 100 times more CO₂ per passenger than airplanes

Rocket launches release significant amounts of water vapor, nitrous oxide, and rocket propellants, which generate greenhouse gases and air pollutants. High-altitude emissions can persist for years, affecting the ozone layer.

Increases in atmospheric carbon dioxide lead plants to produce more pollen

Pollen issues are emerging earlier in the year and lasting longer as rising levels of carbon dioxide in the atmosphere boost plants’ pollen production and also simultaneously extend warmer, pollen-producing seasons.

Where radon comes from and why it may be the most dangerous source of radioactivity

Released from underground bedrock before passing through soil, this radioactive gas is produced from the decay of uranium, thorium, and radium and accounts for about half of all human exposure to radiation. It is the leading cause of lung cancer among nonsmokers and can build up in enclosed spaces such as buildings without proper ventilation to dilute the gas.

City structures cause localized heat zones hotter than nearby rural areas

Urban materials like asphalt and concrete trap heat, while cities lack cooling features like trees and water. Due to hot runoff, urban streams can heat up by as much as 18°F more than forested streams.

Scientists testing how climate change affects plants found, in a years-long simulation study, that poison ivy grew 70% faster with the resulting extra carbon dioxide.

Photochemical smog forms when sunlight reacts with car and industrial emissions

The hazy phenomenon's name is a combination of "smoke" and "fog" and is composed of chemical pollutants that can cause eye irritation, lung damage and harm to crops. Smog buildup is more common in cities with sunny climates, minimal wind and surrounding mountains that trap these chemicals.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

Collisions between cosmic rays and atmospheric particles dwarf particle accelerators

According to Einstein's model of gravity, confining immense energy into a sufficiently small region would warp space-time enough to create a black hole. If accelerators actually did create black holes, then trillions more would be produced daily in the atmosphere, where collisions are millions of times more energetic.

The deadliest aspect of volcanic eruptions is often not lava, but pyroclastic flows—avalanches of ash, gas, and rock that can move more than half the speed of sound.

Volcanic activity may have triggered the Black Death by spewing gases that led to crop failures in Europe, thus forcing the import of grain ships with plague-infested fleas.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

The price of gas is a composite made up of several different factors, with the federal gas tax making up less than 20% of what drivers pay at the pump.

Shooting stars, or meteors, are fragments of asteroids and comets that burn up as they enter Earth's atmosphere, creating streaks in the sky called meteor showers.

How fusion—which releases energy when two lighter atoms combine to form a heavier atom—differs from fission

Listen to an in-depth conversation on the links between Parkinson's disease and herbicide exposure and the challenging pace of scientific investigation.

Electrical grids worldwide must double their power delivery capacity by 2050 to meet surging demand from AI and electric vehicles.

Watch how viruses like Ebola can spill over from animals to humans—and vice-versa.

Double world record holder Hunter Ewen helped conquer his fear of balloons, called globophobia, by training to win Guinness World Record titles for balloon inflation.

Fish populations in the Great Barrier Reef have increased after installing waterproof speakers on the ocean floor that played recordings of sounds from healthy coral reefs.

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.

Massive 3D printers have been used to build homes by stacking layers of 'concrete toothpaste,' a fire-resistant material that effectively insulates against outside noise.

Fireworks-related ER visits are on the rise—in 2024, they increased by 52% as compared to the prior year.

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

Astronauts have repaired genetic damage in space using CRISPR—a molecular tool that can make precise changes to DNA and is used in single-celled organisms to attack invasive viruses.

See the 25 of the best photos of auroras from around the world.

Before writing 'Walden,' transcendentalist Henry David Thoreau nearly burned down his hometown with a campfire that grew out of control.

Louisiana's 'Cancer Alley' is infamous for having some of the highest industrial pollution, toxic air emissions, and cancer risks in the US.

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

The power and influence of the American presidency have expanded significantly over time—far beyond what the founders envisioned.

Fast-casual restaurant Chili's is experiencing a resurgence, with its parent company recently reporting a nearly 32% increase in sales, thanks to passionate Gen Z fans on TikTok.

Existentialist writer Jean-Paul Sartre coined the famous phrase 'Hell is—other people' in his play 'No Exit'