The Köppen-Geiger system divides Earth’s climate into five main categories

View the 55 ECVs used to describe Earth's atmospheric conditions

Essential climate variables include physical, chemical, and biological variables that meaningfully contribute to Earth's climate and how it changes with time. Many of these variables influence one another through feedback mechanisms across Earth's atmosphere, hydrosphere, cryosphere, biosphere, and geosphere.

An overview of Earth's atmospheric cells and how they distribute Earth's uneven heating

The Hadley, Ferrel, and Polar cells are circulation patterns that act like gears, moving warmer air from the equator to the poles. The rising and falling of air currents within these patterns creates semi-persistent regions of low and high pressure, which contribute to the formation of regional climates, such as tropical zones.

View a diagram of Earth's atmosphere, which is composed of five layers

Starting from the surface, the troposphere is home to Earth's weather, followed by the stratosphere, which houses the ozone layer, and the mesosphere, which burns up most debris from space. Above these layers lies the thermosphere, where auroras are produced, and the exosphere, which lacks a clear outer boundary as it fades into outer space.

Accurate climate models incorporate calculus to account for complex feedback loops

The simplest models assume uniformity across the Earth, with incoming energy from the sun being offset by the planet's albedo, or reflectiveness, which prevents the radiation from being fully absorbed. Incorporating elements such as atmospheric layers, latitude bands, geographic variability, and emissivity yields coupled differential equations quantifying Earth's interconnected systems.

Discover trends in Earth's climate system: What are indicators of climate change?

A comprehensive deep dive tracking components of the climate system over time, such as temperature, sea level, sea ice amounts, ocean heat, greenhouse gases, and more (w/charts and graphs).

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.

Meteorological v. astronomical seasons, explained

Meteorologists and climatologists define seasons differently from “regular” or astronomical spring, summer, fall, and winter. Traditional seasons reflect the movement of celestial objects, known as the astronomical seasons; meteorologists mark seasonal change based on temperature averages.

Climate data is monitored globally using tools from satellites to backyard gauges

Scientists use satellites, balloons, ocean buoys, and land-based instruments to track climate variables like temperature, precipitation, and wind. These tools gather data from deep ocean waters to the upper atmosphere.

A breakdown of Earth's atmospheric layers, including why it can get colder or hotter with altitude

Gases in the troposphere—the atmosphere's lowest layer—cool with increasing height as they get farther from the thermal energy emitted by Earth's warm surface. In the next layer—the stratosphere—ozone is increasingly heated by the sun's ultraviolet radiation with height. Because cooler air sinks and hotter air rises, the cooler troposphere and hotter stratosphere form a natural boundary keeping Earth's weather in the lowest layer.

Hot, semiarid, coastal, cold: An overview of the four desert types

This article describes the various characteristics of deserts, including their geography, their climate, their soil, and the wildlife and vegetation that inhabit them. All desert climates are characterized by extreme temperatures and low rainfall,...

What's the difference between weather and climate?

A five-minute TedEd video exploring the differences between weather and climate – what they are, how we predict them, and what those predictions can tell us.

The field of attribution science seeks to determine whether specific phenomena, such as melting glaciers, droughts, and hurricanes, are driven by Earth's natural climate cycles or by human-caused climate change.

The greenhouse effect was discovered by analyzing Earth's temperature

Using mathematical techniques developed to analyze heat transfer, Jean-Baptiste Joseph Fourier showed that Earth should be significantly cooler if solar radiation were the only contributor to its surface temperature. By considering that the atmosphere could amplify the sun's warming effect, he formulated what became known as the greenhouse effect.

Explore a series of interdisciplinary explainers on climate science

From animations on the quantum mechanics of greenhouse gases to a photo essay on how scientists acquire climate data, this collection provides detailed explorations of how different branches of science have contributed to our understanding of climatology.

Climate models use complex equations and supercomputers to predict future climate

The equations apply the laws of thermodynamics, fluid motion, and radiative transfer to a 3D grid along Earth's surface. After solving them for each cell in the grid over a time interval, the results carry over to neighboring cells, and the process repeats into the future.

Explore Earth's future climate under different levels of warming

An incredible interactive project showing how global warming is projected to affect the world, from temperatures to rainfall, droughts and flooding, and more.

Explore a simulation of the greenhouse effect

Investigate how cloud cover, surface albedo—a measure of a surface's reflectiveness—greenhouse concentrations, and atmospheric layers affect the energy balance on a simulated planet. Using either the wave or particle models of light, users can also explore how changes in solar intensity affect planetary surface temperature.

The way hurricanes are categorized may mislead the public to their dangers

The Saffir-Simpson scale categorizes hurricanes based on wind speed, but tropical cyclones' main dangers are storm surges and heavy rainfall. To better communicate risks to the public, a new system that incorporates hurricane size, water content, and other complexities should be developed.

A map of extreme weather events and their links to climate change

To track how the evidence on this fast-moving topic is stacking up, Carbon Brief has mapped every extreme-weather attribution study published to date. Read more about the findings from the comprehensive analysis.

The impact of greenhouse gases is assessed as a measure of Global Warming Potential

Since 1990, the Intergovernmental Panel on Climate Change has used GWP to measure how much energy 1 metric ton of a gas emits over a given period—usually 100 years—relative to 1 metric ton of carbon dioxide. By definition, carbon dioxide has a GWP of 1.

Climatologists use past data and advanced models to forecast future climate trends

Unlike meteorology, which focuses on weather forecasting over several days, climatology identifies trends in data over periods of 30 or more years. This data can go back millions of years and help refine models to forecast centuries into the future.

Hurricanes are classified according to their maximum sustained wind speed

The Saffir-Simpson Hurricane Wind Scale is a rating system that organizes hurricanes into one of five categories. Categories three and higher are classified as major hurricanes, but all categories can produce deadly storm surges and rain-induced floods.

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.

The Kardashev scale measures a civilization's advancement based on energy use

Developed by Russian astrophysicist Nikolai Kardashev in 1964, the scale classifies a civilization based on the amount of energy its existing technologies can harness, ranging from a society that consumes as much energy as a single planet to one that consumes as much energy as an entire galaxy.

The three categories of photosynthesis, which each help plants survive in different environments

In the vast majority of plants, C3 photosynthesis produces three-carbon intermediate molecules in the Calvin cycle within the cells of leaves. Plants in hot, dry climates use C4 photosynthesis across two types of cells to produce four-carbon molecules before the Calvin cycle. Plants in drought conditions use CAM to store carbon dioxide as an acid at night, minimizing water loss.

The complexity of classifying a tree

It may seem obvious to us when we see a tree, but very specific characteristics cause scientists to distinguish trees from other types of plants. This video provides a visual and verbal explanation of distinctions that separate trees from other plants like shrubs or herbs. See a scientific breakdown of these traits.

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.

Understanding the 1.5 degree Celsius climate benchmark

As more parts of the world are facing extreme weather, from high temperatures to increased natural disasters, there is much debate about what can be done. MIT News explores and explains the 1.5-degree benchmark for limiting the effects of climate change. Read to understand where the planet stands in relation to this threshold and what can be done at the global, regional, and personal levels to “keep 1.5 alive.”

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...

Climate determinism wrongly linked human traits and societal progress to geography

Historically rooted in Greek philosophy, its ideas used the latitudes where people were located to justify racial hierarchies, casting tropical peoples as lazy or inferior. These biases still influence how media and research portray people in climatically disadvantaged regions. (Some readers may experience a paywall.)

Explore an interactive global weather map, with overlays depicting real-time data on temperature, precipitation, wind, humidity, and pressure, which enable the tracking and monitoring of extreme weather events.

Just as landmasses have been divided into distinct nations, the world ocean has been divided into multiple oceans for various geographical, practical, and scientific reasons.

Explore how temperatures compare to historical averages in cities worldwide with this interactive global monitor.

As of 2022, just 0.5% of installed renewable energy capacity worldwide is geothermal

Despite being able to generate electricity regardless of the weather, solar (28%) and wind (27%) are far more prevalent, primarily because of their lower upfront costs. Geothermal plants use 88% less space than solar farms to produce the same energy, but have been restricted to geologically active regions.

B2 models the interactions of air, water, soil, plants and microbes at the LEO

The Landscape Evolution Observatory at Biosphere 2 examines how factors such as climate change, water flow, weathering and community development impact landscape structures comprising 500 metric tons of crushed rock. Research is also conducted at biomes representing savannas, mangroves, coastal fog deserts, oceans and rainforests.

Earth has shifted between extreme warming and cooling phases for 500 million years

Earth is in an interglacial period of the Quaternary glaciation, resulting in receding glaciers and mild temperatures. However, today's warming trend is occurring much faster than previous warming periods in the climate record.

Scientists quantify how far from the poles auroras will be visible using the G-scale

The Geomagnetic Storm scale indicates the expected severity of the deformation of Earth's magnetic field based on the amount of energy injected by the solar wind. Solar activity is monitored using various satellites to forecast these storms, which can also be used to anticipate damage and disruption to power systems, radio communications, and satellite navigation.

How is the climate like baseball?

A two-minute video taking a lighthearted look at an unexpected analogy, explaining why some people call carbon dioxide (and the other greenhouse gases) the steroids of the climate system.

Learn all about different types of extreme weather

Find out in more detail about different types of extreme weather, from flooding to thunderstorms, from tropical cyclones to sandstorms, and more (w/ helpful videos).

An overview of the anthropocene: the scale of human influence on Earth

Human activity has fundamentally changed our planet. We live on every continent and have directly affected at least 83% of the planet’s viable land surface.

Explore which sectors produce the most greenhouse gas emissions by country

As of 2023, the energy sector, including electricity and heating, accounts for the largest share of greenhouse gas emissions. The 10 largest greenhouse gas-emitting nations account for two-thirds of global emissions, with the world's top three—China, the US, and India—contributing 15 times more than the bottom 100.

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.

Mapping how the El Niño-Southern Oscillation affects weather patterns around the world

In the warm episode (El Niño), summers in India, Indonesia, Australia, and the Caribbean are drier than normal, while winters bring wetter, cooler conditions to the US Gulf Coast and warmer conditions to the Pacific Northwest. During the cold episode (La Niña), these are reversed, with India, Indonesia, and the southern Caribbean experiencing greater rainfall in the summers.

What are climate models?

Climate modeling what is a global climate model? What are their uses? Why do we believe them? What do they agree on? Why do they disagree? How do we improve them?

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.

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.

Most coffee is grown within the coffee belt, a geographic region characterized by mild climates, regular rainfall, and higher altitudes.

Differences in pressure and temperature between atmospheric gases create wind

Because Earth's surface is not uniformly heated by the sun at all times, pockets of warmer and cooler air will form and interact. Warmer pockets of less dense air will rise, leaving gaps for cooler, denser air to move in. Wind is this movement of air from high-pressure to low-pressure areas.

Explore an interactive visualization of greenhouse gas emissions from 745 million sources worldwide.

Climate tipping points are irreversible changes to Earth's environment

Earth's natural systems have prevented these events—including the mass death of coral reefs, loss of the Amazon rainforest, and shutdown of Atlantic currents—but scientists believe they are unlikely to withstand continued stressors from climate change.