How Earth’s Climate Changes Naturally (and Why Things Are Different Now) (2024)

Faint Young Sun

Magnitude: No net temperature effect

Time frame: Constant

Though the sun’s brightness fluctuates on shorter timescales, it brightens overall by 0.009% per million years, and it has brightened by 48% since the birth of the solar system 4.5 billion years ago.

Scientists reason that the faintness of the young sun should have meant that Earth remained frozen solid for the first half of its existence. But, paradoxically, geologists have found 3.4-billion-year-old rocks that formed in wave-agitated water. Earth’s unexpectedly warm early climate is probably explained by some combination of less land erosion, clearer skies, a shorter day and a peculiar atmospheric composition before Earth had an oxygen-rich atmosphere.

Clement conditions in the second half of Earth’s existence, despite a brightening sun, do not create a paradox: Earth’s weathering thermostat counteracts the effects of the extra sunlight, stabilizing Earth’s temperature (see next section).

Carbon Dioxide and the Weathering Thermostat

Magnitude: Counteracts other changes

Time frame: 100,000 years or longer

The main control knob for Earth’s climate through deep time has been the level of carbon dioxide in the atmosphere, since carbon dioxide is a long-lasting greenhouse gas that blocks heat that tries to rise off the planet.

Volcanoes, metamorphic rocks and the oxidization of carbon in eroded sediments all emit carbon dioxide into the sky, while chemical reactions with silicate minerals remove carbon dioxide and bury it as limestone. The balance between these processes works as a thermostat, because when the climate warms, chemical reactions become more efficient at removing carbon dioxide, putting a brake on the warming. When the climate cools, reactions become less efficient, easing the cooling. Consequently, over the very long term, Earth’s climate has remained relatively stable, providing a habitable environment. In particular, average carbon dioxide levels have declined steadily in response to solar brightening.

However, the weathering thermostat takes hundreds of thousands of years to react to changes in atmospheric carbon dioxide. Earth’s oceans can act somewhat faster to absorb and remove excess carbon, but even that takes millennia and can be overwhelmed, leading to ocean acidification. Each year, the burning of fossil fuels emits about 100 times more carbon dioxide than volcanoes emit — too much too fast for oceans and weathering to neutralize it, which is why our climate is warming and our oceans are acidifying.

Plate Tectonics

Magnitude: Roughly 30 degrees Celsius over the past 500 million years

Time frame: Millions of years

The rearrangement of land masses on Earth’s crust can slowly shift the weathering thermostat to a new setting.

The planet has generally been cooling for the last 50 million years or so, as plate tectonic collisions thrust up chemically reactive rock like basalt and volcanic ash in the warm, wet tropics, increasing the rate of reactions that draw carbon dioxide from the sky. Additionally, over the last 20 million years, the building of the Himalayas, Andes, Alps and other mountains has more than doubled erosion rates, boosting weathering. Another contributor to the cooling trend was the drifting apart of South America and Tasmania from Antarctica 35.7 million years ago, which initiated a new ocean current around Antarctica. This invigorated ocean circulation and carbon dioxide–consuming plankton; Antarctica’s ice sheets subsequently grew substantially.

Earlier, in the Jurassic and Cretaceous periods, dinosaurs roamed Antarctica because enhanced volcanic activity, in the absence of those mountain chains, sustained carbon dioxide levels around 1,000 parts per million, compared to 415 ppm today. The average temperature of this ice-free world was 5 to 9 degrees Celsius warmer than now, and sea levels were around 250 feet higher.

Asteroid Impacts

Magnitude: Approximately 20 degrees Celsius of cooling followed by 5 degrees Celsius of warming (Chicxulub)

Time frame: Centuries of cooling, 100,000 years of warming (Chicxulub)

The Earth Impact Database recognizes 190 craters with confirmed impact on Earth so far. None had any discernable effect on Earth’s climate except for the Chicxulub impact, which vaporized part of Mexico 66 million years ago, killing off the dinosaurs. Computer modeling suggests that Chicxulub blasted enough dust and sulfur into the upper atmosphere to dim sunlight and cool Earth by more than 20 degrees Celsius, while also acidifying the oceans. The planet took centuries to return to its pre-impact temperature, only to warm by a further 5 degrees Celsius, due to carbon dioxide in the atmosphere from vaporized Mexican limestone.

How or whether volcanic activity in India around the same time as the impact exacerbated the climate change and mass extinction remains controversial.

Evolutionary Changes

Magnitude: Depends on event; about 5 degrees Celsius cooling in late Ordovician (445 million years ago)

Time frame: Millions of years

Occasionally, the evolution of new kinds of life has reset Earth’s thermostat. Photosynthetic cyanobacteria that arose some 3 billion years ago, for instance, began terraforming the planet by emitting oxygen. As they proliferated, oxygen eventually rose in the atmosphere 2.4 billion years ago, while methane and carbon dioxide levels plummeted. This plunged Earth into a series of “snowball” climates for 200 million years. The evolution of ocean life larger than microbes initiated another series of snowball climates 717 million years ago — in this case, it was because the organisms began raining detritus into the deep ocean, exporting carbon from the atmosphere into the abyss and ultimately burying it.

When the earliest land plants evolved about 230 million years later in the Ordovician period, they began forming the terrestrial biosphere, burying carbon on continents and extracting land nutrients that washed into the oceans, boosting life there, too. These changes probably triggered the ice age that began about 445 million years ago. Later, in the Devonian period, the evolution of trees further reduced carbon dioxide and temperatures, conspiring with mountain building to usher in the Paleozoic ice age.

Large Igneous Provinces

Magnitude: Around 3 to 9 degrees Celsius of warming

Time frame: Hundreds of thousands of years

Continent-scale floods of lava and underground magma called large igneous provinces have ushered in many of Earth’s mass extinctions. These igneous events unleashed an arsenal of killers (including acid rain, acid fog, mercury poisoning and destruction of the ozone layer), while also warming the planet by dumping huge quantities of methane and carbon dioxide into the atmosphere more quickly than the weathering thermostat could handle.

In the end-Permian event 252 million years ago, which wiped out 81% of marine species, underground magma ignited Siberian coal, drove up atmospheric carbon dioxide to 8,000 parts per million and raised the temperature by between 5 and 9 degrees Celsius. The more minor Paleocene-Eocene Thermal Maximum event 56 million years ago cooked methane in North Atlantic oil deposits and funneled it into the sky, warming the planet by 5 degrees Celsius and acidifying the ocean; alligators and palms subsequently thrived on Arctic shores. Similar releases of fossil carbon deposits happened in the end-Triassic and the early Jurassic; global warming, ocean dead zones and ocean acidification resulted.

If any of that sounds familiar, it’s because human activity is causing the same effects today.

As a team of researchers studying the end-Triassic event wrote in April in Nature Communications, “Our estimates suggest that the amount of CO2 that each … magmatic pulse injected into the end-Triassic atmosphere is comparable to the amount of anthropogenic emissions projected for the 21st century.”

Update:July 24, 2020
An earlier version of this article included a chart of carbon dioxide and oxygen concentrations through deep time. That chart was based on a single data source and does not reflect the best available modern evidence. It has been removed it from the article.

How Earth’s Climate Changes Naturally (and Why Things Are Different Now) (2024)


How has Earth's climate changed naturally? ›

The earth's climate is influenced and changed through natural causes like volcanic eruptions, ocean currents, the Earth's orbital changes, solar variations and internal variability.

Why the current changes in Earth's climate is different from the past changes? ›

Today's climate change is different from past climate change in several important ways: Natural causes are not responsible. None of the natural causes of climate change, including variations in the sun's energy and the Earth's orbit, can fully explain the climate changes we are seeing today.

How the Earth's climate has changed over time? ›

According to NOAA's 2021 Annual Climate Report the combined land and ocean temperature has increased at an average rate of 0.14 degrees Fahrenheit ( 0.08 degrees Celsius) per decade since 1880; however, the average rate of increase since 1981 has been more than twice as fast: 0.32 °F (0.18 °C) per decade.

How has the climate change and why does it matter? ›

Climate change is transforming our planet, and extreme weather events, rising sea levels, and wildfires are becoming more common. Most of these issues have been caused by humans adding heat-trapping greenhouse gases (carbon dioxide, methane, and nitrous oxide) to Earth's atmosphere from fossil fuel combustion.

What are the 5 main causes of climate change? ›

Causes of Climate Change
  • Generating power. Generating electricity and heat by burning fossil fuels causes a large chunk of global emissions. ...
  • Manufacturing goods. ...
  • Cutting down forests. ...
  • Using transportation. ...
  • Producing food. ...
  • Powering buildings. ...
  • Consuming too much.

What are natural changes in the environment? ›

The processes of natural change include geo- logic changes, plant and animal succession, and change as a response to weather. Geologic change refers to the way the land may be altered as the result of erosion, uplift, or volcanism. Succession refers to plant and animal changes in an ecosystem over time.

How is global climate change today different than ever before? ›

Since the pre-industrial period, human activities are estimated to have increased Earth's global average temperature by about 1 degree Celsius (1.8 degrees Fahrenheit), a number that is currently increasing by more than 0.2 degrees Celsius (0.36 degrees Fahrenheit) per decade.

Why has climate change changed suddenly? ›

Most abrupt climate shifts are likely due to sudden circulation shifts, analogous to a flood cutting a new river channel. The best-known examples are the several dozen shutdowns of the North Atlantic Ocean's Meridional Overturning Circulation during the last ice age, affecting climate worldwide.

Why has Earth's climate changed so rapidly in recent years? ›

Greenhouse gases in the atmosphere absorb heat radiation. Human activity has increased greenhouse gases in the atmosphere since the Industrial Revolution, leading to more heat retention and an increase in surface temperatures.

How often does Earth's climate naturally change? ›

Interannual to Decadal Climate Cycles

ENSO events occur every 3 to 7 years, and bring different weather conditions to different parts of the world (NASA 2009).

How much of climate change is natural? ›

The most recent special report on global warming of 1.5 degrees confirms that the observed changes in global and regional climate over the last 50 or so years are almost entirely due to human influence on the climate system and not due to natural causes.

How does climate change affect our everyday life? ›

Climate change affects human health and wellbeing through more extreme weather events and wildfires, decreased air quality, and diseases transmitted by insects, food, and water.

How does climate change affect everything? ›

Drought can harm food production and human health. Flooding can lead to disease spread and damages to ecosystems and infrastructure. Human health issues can increase mortality, impact food availability, and limit worker productivity. Climate change impacts are seen throughout every aspect of the world we live in.

Why is climate change one of the biggest problems? ›

Humans and wild animals face new challenges for survival because of climate change. More frequent and intense drought, storms, heat waves, rising sea levels, melting glaciers and warming oceans can directly harm animals, destroy the places they live, and wreak havoc on people's livelihoods and communities.

Why is climate change a problem essay? ›

The climatic change has become a global concern over the last few decades. Besides, these climatic changes affect life on the earth in various ways. These climatic changes are having various impacts on the ecosystem and ecology. Due to these changes, a number of species of plants and animals have gone extinct.

What are the 3 main natural causes of climate change? ›

These have been caused by many natural factors, including changes in the sun, emissions from volcanoes, variations in Earth's orbit and levels of carbon dioxide (CO2).

What are the 3 main effects of climate change? ›

The potential future effects of global climate change include more frequent wildfires, longer periods of drought in some regions, and an increase in the duration and intensity of tropical storms.

What are the 3 main causes of climate change? ›

Burning fossil fuels, cutting down forests and farming livestock are increasingly influencing the climate and the earth's temperature. This adds enormous amounts of greenhouse gases to those naturally occurring in the atmosphere, increasing the greenhouse effect and global warming.

What are some examples of natural causes of climate change? ›

Natural Causes of Climate Change

Over the course of Earth's existence, volcanic eruptions, fluctuations in solar radiation, tectonic shifts, and even small changes in our orbit have all had observable effects on planetary warming and cooling patterns.

What is natural climate change examples? ›

Natural causes of climate change

The earth has gone through warming and cooling phases in the past, long before humans were around. Forces that can contribute to climate change include the sun's intensity, volcanic eruptions, and changes in naturally occurring greenhouse gas concentrations.

What is an example of natural change? ›

Examples of natural changes: wilting of leaves from trees and melting of snow on mountains.

What is different about climate change in modern times? ›

Other observations of recent climate change include: a global average sea level rise of 8 inches since the late 19th century; declining sea ice, ice sheet, and glacier size; changing patterns in rain and snowfall; decreased snow cover and longer frost-free seasons; and more frequent high-temperature records being set ...

How is climate change different around the world? ›

Changes in Earth's climate have different effects in different areas of the world. Some places will warm much more than others, some regions will receive more rainfall, while others are exposed to more frequent droughts. Regional changes in temperature and precipitation are having impacts on people and ecosystems.

Has the climate always changed its natural? ›

The Earth's climate has always changed. Over the course of the Earth's 4.5-billion-year history, the climate has changed a lot. This is true. But the rapid warming we're seeing now can't be explained by natural cycles of warming and cooling.

What are the natural cycles of climate change? ›

Orbital Wobbles

Earth's orbit wobbles as the sun, the moon and other planets change their relative positions. These cyclical wobbles, called Milankovitch cycles, cause the amount of sunlight to vary at middle latitudes by up to 25% and cause the climate to oscillate.

What are natural drivers of climate change? ›

Natural climate drivers include changes in the sun's energy output, regular changes in Earth's orbital cycle, and large volcanic eruptions that put light-reflecting particles into the upper atmosphere.

How is the Earth changing today? ›

High temperature extremes and heavy precipitation events are increasing, glaciers and snow cover are shrinking, and sea ice is retreating. Seas are warming, rising, and becoming more acidic, and flooding is become more frequent along the U.S. coastline.

What is a climate change essay? ›

The climate change essay is information on changing weather conditions and its impact on the environment.

What people are affected by climate change? ›

Other groups that are particularly vulnerable to the health effects of climate change include: pregnant women, immigrant groups (including those with limited English proficiency), indigenous peoples, the disabled, vulnerable occupational groups, such as workers who are exposed to extreme weather, and people with pre- ...

What are 5 ways climate change will affect you? ›

Trauma from floods, droughts, and heat waves can lead to mental health issues like anxiety, depression, and suicide. More heat can mean longer allergy seasons and more respiratory disease. More rain increases mold, fungi, and indoor air pollutants. Mosquito-borne dengue fever has increased 30-fold in the past 50 years.

What is conclusion on climate change? ›

In conclusion, climate change is the most significant problem facing the world. Global warming is increasing day by day. If we cannot prevent it as soon as possible, our world will face undesirable consequences.

How long do humans have left on earth? ›

There have been a number of other estimates of existential risk, extinction risk, or a global collapse of civilization: Humanity has a 95% probability of being extinct in 7,800,000 years, according to J.

What is the main issue of climate change? ›

The main threats of climate change, stemming from the rising temperature of Earth's atmosphere include rising sea levels, ecosystem collapse and more frequent and severe weather. Rising temperatures from human-caused greenhouse gas emissions affects planet-wide systems in various ways.

What will happen if we don't stop climate change? ›

Global warming increases the risk of more frequent—and heavier—rainfall, snowfall, and other precipitation. And as that risk increases, so too does the risk of flooding.

Why should we care about climate change? ›

From more extreme weather to increasing food prices, to recreation and decreased opportunities to appreciate the natural world, people everywhere will feel its effects. Reducing our carbon footprint is fundamentally necessary to create a world where people and nature thrive – and that's why WWF is working on it.

How can we solve the problem of climate change? ›

What Are the Solutions to Climate Change?
  1. Ending Our Reliance on Fossil Fuels.
  2. Greater Energy Efficiency.
  3. Renewable Energy.
  4. Sustainable Transportation.
  5. Sustainable Buildings.
  6. Better Forestry Management and Sustainable Agriculture.
  7. Conservation-Based Solutions.
  8. Industrial Solutions.
Dec 13, 2022

How can we help solve climate change? ›

What are the solutions to climate change?
  1. Keep fossil fuels in the ground. ...
  2. Invest in renewable energy. ...
  3. Switch to sustainable transport. ...
  4. Help us keep our homes cosy. ...
  5. Improve farming and encourage vegan diets. ...
  6. Restore nature to absorb more carbon. ...
  7. Protect forests like the Amazon. ...
  8. Protect the oceans.

Is global warming man made or natural? ›

Scientists agree that global warming is caused mainly by human activity.

Is Earth's climate always changing? ›

The Earth's climate is always changing, but human-caused climate change today is unlike any other period in our planet's history. The Earth's climate and atmosphere have changed drastically over the last 4.5 billion years.

Would climate change happen anyway? ›

Humans have caused major climate changes to happen already, and we have set in motion more changes still. However, if we stopped emitting greenhouse gases today, the rise in global temperatures would begin to flatten within a few years. Temperatures would then plateau but remain well-elevated for many, many centuries.

Why is climate change a problem? ›

Humans and wild animals face new challenges for survival because of climate change. More frequent and intense drought, storms, heat waves, rising sea levels, melting glaciers and warming oceans can directly harm animals, destroy the places they live, and wreak havoc on people's livelihoods and communities.

What are the natural causes of global warming essay? ›

The natural causes include the release of greenhouses gases which are not able to escape from earth, causing the temperature to increase. Further, volcanic eruptions are also responsible for global warming. That is to say, these eruptions release tons of carbon dioxide which contributes to global warming.

What are 3 most important factors that influence climate? ›

The most important natural factors are: distance from the sea. ocean currents. direction of prevailing winds.

What are the 6 natural factors that affect the climate? ›

There are six major natural climate factors: air masses and winds, latitude, ocean currents, elevation, relief, and bodies of water. Some are global factors that affect all parts of Earth.

Can we stop climate change? ›

Yes. While we cannot stop global warming overnight, we can slow the rate and limit the amount of global warming by reducing human emissions of heat-trapping gases and soot (“black carbon”).

What causes global warming not man made? ›

Natural Causes of Warming

Natural factors include continental drift and mountain-building, changes in the Earth's orbit, volcanic eruptions, and solar variability. Different factors operate on different time scales.

How can we slow down man made climate change? ›

10 Ways to Stop Global Warming
  1. Change a light. Replacing one regular light bulb with a compact fluorescent light bulb will save 150 pounds of carbon dioxide a year.
  2. Drive less. ...
  3. Recycle more. ...
  4. Check your tires. ...
  5. Use less hot water. ...
  6. Avoid products with a lot of packaging. ...
  7. Adjust your thermostat. ...
  8. Plant a tree.

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