Climate Change Explainers

Get answers to questions about climate change science, solutions, and related topics, written by scientists and experts via the MIT Climate Portal.

MIT Climate Portal avatar
99 articles in this collection
Written by MIT Climate Portal
Oceans

Phytoplankton

By taking up carbon dioxide (CO2) from the air, phytoplankton play a large role in the natural carbon cycle, helping to regulate the ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Ocean Acidification

Ocean acidification refers to a gradual increase in the acidity of ocean water, caused mainly by human-emitted carbon dioxide mixing with...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Coastal Ecosystems and Climate Change

Coastal ecosystems, formed by plants that can thrive in saltwater, are especially good at storing carbon because of the thick, rich ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Sea Level Rise

Sea levels around the world are rising because of climate change, as warming ocean waters and melting ice cause the oceans to encroach ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

How will future warming and CO2 emissions affect oxygen concentrations?

Oxygen levels are declining due to the burning of fossil fuels and other kinds of pollution. While the decline won’t directly affect ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

How many new trees would we need to offset our carbon emissions?

Because of the complexity of the carbon cycle, the answer is not obvious. What is obvious, MIT experts say, is that we should not only...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

How will coastal residents first experience the effects of sea level rise?

People on the coasts may find that the biggest effects from rising seas will come from the groundwater below their feet.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

How do hurricanes affect coastal and ocean life?

Hurricanes can radically affect marine ecosystems, changing seafloor habitats as well as levels of oxygen, salinity, and pollution...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Why is the ocean so important for climate change?

The ocean acts as a “buffer” that protects our atmosphere from seeing the full effects of climate change.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago
Top Solutions

Why isn’t my kid learning about climate change in their high school classroom?

In the U.S., climate change is not a standard part of the public school curriculum in many districts due to a lack of resources, lack of ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

How much is captured CO2 worth?

Facilities using carbon capture usually can't sell large amounts of CO2 in commercial markets—but in the U.S., thanks to tax credits...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated today

Are electric vehicles definitely better for the climate than gas-powered cars?

Yes: although electric cars' batteries make them more carbon-intensive to manufacture than gas cars, they more than make up for it by ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Net Zero Emissions

Some actions, like using electricity from a fossil fuel-fired power plant, lead to greenhouse gases entering the atmosphere.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Renewable Energy

Renewable energy is energy from sources, like wind, solar, and hydropower, that we cannot run out of.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Would stopping plastic pollution help with climate change? How do we do it?

Plastic pollution does contribute a bit to climate change—and slowing the production of non-degradable plastics has other large benefits ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Climate Targets

Targets are the limits that scientists and policymakers set in plans to combat climate change. These targets can take different forms ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Does the concrete needed to build renewable energy cancel out the benefits?

It takes fossil fuels to build renewable energy infrastructure such as solar panels and wind turbines, but those emissions pale in...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Why did the IPCC choose 2°C as the goal for limiting global warming?

Scientists and policymakers have long agreed that global warming beyond 2° C above the pre-industrial average would pose large and ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Will mining the resources needed for clean energy cause problems for the environment?

Almost all mining—including for the clean tech sector—damages ecosystems and communities. Water contamination and scarcity, and the ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

What is “sustainability”? Is it the same thing as taking action on climate change?

Climate action is just one form of sustainability—a concept that asks us to see the big picture of what we are taking from the Earth, and...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Do we have the technology to go carbon neutral today?

We still need new breakthroughs to decarbonize many parts of our modern economy, especially if we don’t want to drive up the price of...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

The Paris Agreement

The Paris Climate Agreement is a treaty that brings all the world’s peoples into a common effort to combat climate change.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Why have I heard that eating meat is bad for the climate?

Meat directly produces greenhouse gas emissions and requires more land and other resources than plant-based foods.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

What method of waste disposal is best for the climate?

All waste disposal methods release greenhouse gases, and it's hard to make apples-to-apples comparisons. But there's only one solution...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Why don’t we use tidal power more?

Tidal power is a promising renewable energy source, but production costs, a limited number of suitable locations, and technological ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

If cities require new buildings to use 100% electric heat, will that raise or lower their greenhouse gas emissions?

Electric heating can cause a short-term rise in emissions in areas that get their electricity from fossil fuels. But without electric ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

How are countries held accountable under the Paris Agreement?

The short answer is that there is no hard enforcement in the Paris Agreement. But all the members regularly meet, share progress, and ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago
Technology

Investing and Climate Change

Investors trade over $250 trillion worth of stocks, bonds and other long-term investments in global capital markets every year ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

How do national governments calculate their share of greenhouse gas emissions from international air travel?

They don't—emissions from international flights are counted separately from any one country's emissions. But there are several ideas to ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

How efficient is carbon capture and storage?

Most carbon capture technologies aim to stop at least 90% of the CO2 in smokestacks from reaching the atmosphere. But as the technology ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Can we cool the Earth by covering more of it with snow?

More snow cover could reflect more sunlight back into space. But tinkering with the climate is not something to be taken lightly.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Cities and Climate Change

Cities concentrate people into small areas for good reason. From the smallest towns to sprawling metropolitan regions of more than ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

The Electric Grid

The electric grid is a network of power lines and other infrastructure that moves electricity from power plants to our homes and ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Climate-Resilient Infrastructure

As climate change causes weather disasters to become more severe or reach new areas, much of our infrastructure will need to be ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Carbon Capture

Carbon capture and storage is a technology that captures the carbon dioxide from burning fossil fuels before it is released to the ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Nuclear Energy

Nuclear energy is energy made by breaking the bonds that hold particles together inside an atom, a process called “nuclear fission.” ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Mining and Metals

Mining provides us with the building blocks of modern society. Think about all the commonplace objects that contain metals – washing ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Aviation

Aviation emissions are responsible for around 5% of climate warming, and this share is rising.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Concrete

Concrete is among the world’s most consumed materials—second only to water. It also produces large amounts of heat-trapping greenhouse...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Energy Storage

Energy storage is technology that holds energy at one time so it can be used at another time. Cheap and abundant energy storage is a key...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Which is more likely: electric airplanes or hydrogen-powered airplanes?

For long-range flights with many passengers, liquid fuels like hydrogen are probably our best bet.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Carbon Pricing

Carbon pricing is a policy tool to lower emissions of carbon dioxide and other greenhouse gases, by putting a tax or other price on them.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Is there a place in the atmosphere where carbon dioxide is concentrated, and if so, can we remove it?

Carbon dioxide mixes evenly through the atmosphere. But the atmosphere as a whole is densest near the ground, so a cubic foot of air at ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

How much CO2 is emitted by manufacturing batteries?

It depends exactly where and how the battery is made—but when it comes to clean technologies like electric cars and solar power, even the...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

How are gases in the atmosphere analyzed and measured?

By shining different kinds of light and radiation through air samples, scientists can tell which gases are absorbing or reacting to that ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Is there enough titanium to support the growth of electric vehicle production in the US?

In car manufacturing, titanium is primarily used within the exhaust system of gasoline-powered vehicles and can be found in engine parts ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Is there a danger that pumping liquid carbon dioxide underground could have the same negative impacts as fracking?

Pumping carbon dioxide deep underground can cause earthquakes under certain conditions, but there are ways to prevent this.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Freight Transportation

Freight transportation plays an important role in our global economy. Billions of tons of cargo are transported around the world each ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Could Snowpiercer actually happen?

Not accidentally—there would need to be deliberate efforts over many generations to get an ice-covered Earth. But geoengineering to ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Hydrogen

Hydrogen is the lightest chemical element and the most abundant chemical substance in the universe. Using fossil fuels or clean ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Can taking carbon dioxide from the atmosphere and splitting it into carbon and oxygen help stem the tide of rising greenhouse gases?

While CO2 molecules can be broken down and re-used, there are some technological hurdles to clear before we can do this cheaply, put the ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Fusion Energy

Fusion energy is the source of energy at the center of stars, including our own sun. Stars, like most of the universe, are made up of ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago
Weather and Climate

Will climate change make weather forecasting less accurate?

No—because modern weather forecasts use atmospheric physics instead of historical data, they should be reliable even in a world with a...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated today

Hurricanes

Hurricanes are intense tropical cyclones. These storms are becoming stronger as climate change warms the oceans.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Why does burning coal generate more CO2 than oil or gas?

Coal contains more carbon than oil or gas. When we burn these fuels, the higher amount of carbon in coal reacts to form CO2, while a ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated this week

Greenhouse Gases

Greenhouse gases are gases—like carbon dioxide, methane, and nitrous oxide—that keep the Earth warmer than it would be without them.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Extreme Heat

Extreme heat is a dangerous weather condition that is becoming more common and severe as climate change warms the planet.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Climate Models

Climate models are computer programs that simulate weather patterns over time. Scientists use these models to predict how the climate ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Don't plants do better in environments with very high CO2?

Because plants use carbon dioxide to grow, it’s tempting to think they might prefer a planet with more atmospheric CO2 than is present ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Climate Sensitivity

Climate sensitivity is a term used by the Intergovernmental Panel on Climate Change (IPCC) to describe to what extent rising levels of ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Radiative Forcing

Radiative forcing is what happens when the amount of energy that enters the Earth’s atmosphere is different from the amount of energy ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Will climate feedback loops push us past a “point of no return”?

Tripping the Earth's climate feedback loops could bring us rapid warming that would be hugely damaging in the near term. But over the ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

The Intergovernmental Panel on Climate Change

The Intergovernmental Panel on Climate Change (IPCC) collects, reviews, and summarizes the best information on climate change and its ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

The National Climate Assessment

The U.S. Global Change Research Program (USGCRP) is a federal program charged with coordinating climate research across the U.S. ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

How much carbon dioxide does the Earth naturally absorb?

The planet naturally releases and absorbs far more carbon dioxide than humans emit by burning fossil fuels. The problem is that human ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

When scientists say the Earth has warmed by 1° Celsius, which parts of the planet are being measured?

The parts of the planet being measured are our land and ocean surfaces: what we call global average surface temperatures.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

How do greenhouse gases trap heat in the atmosphere?

Greenhouse gas molecules in the atmosphere absorb light, preventing some of it from escaping the Earth. This heats up the atmosphere...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Why do some people call climate change an “existential threat”?

The phrase can refer to a literal threat to humanity’s existence, but also to the danger that unchecked climate change can pose to our ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Why do we compare methane to carbon dioxide over a 100-year timeframe? Are we underrating the importance of methane emissions?

This greenhouse gas is short-lived but has far greater heat-trapping potential than CO2. The more concerned we are about global warming ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

What is the ideal level of carbon dioxide in the atmosphere for human life?

Atmospheric CO2 levels of between 280 and 350 parts per million created the climate that let humanity build and feed the modern world ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

How much is a ton of carbon dioxide?

In 2019, humans emitted more than 35 billion tons of carbon dioxide (CO2) into the atmosphere by burning fossil fuels. It can be ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Has there been climate change before?

The Earth’s climate is always changing, but human-caused climate change today is unlike any other period in our planet’s history.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Should we be worried about Earth getting warmer if we cut coal power?

Coal plants, despite some cooling effects from their complex mix of pollutants, are a major contributor to global warming. If we shut ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

How is climate change affecting the weather today?

Our planet is not only getting warmer—it’s also getting wetter. That shows up in ways both subtle and alarming.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Permafrost

During the Arctic’s short summers, meadows fill up with wildflowers and other greenery. But just a meter or so below the surface, the ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago
Economics

Carbon Offsets

Carbon offsets are tradable “rights” or certificates linked to activities that lower the amount of carbon dioxide (CO2) in the ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

How expensive is it to switch to lower-carbon energy in my own home?

If you can afford to make some investments upfront, you may actually save money in the long run by using lower-carbon energy.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

What is the most cost-effective way to buy carbon offsets?

Offset sellers make it easy to compare prices across projects—but you should also make sure you can trust that your purchase is really ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Will companies pass on the cost of a carbon tax to consumers?

They could, but companies will still face pressure to clean up their greenhouse gas emissions—and there are ways to relieve the burden...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

How can carbon emissions from freight be reduced?

Although most of the world’s cargo moves by ship, focusing on land may be the best way to reduce the carbon footprint of freight.
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

With low-carbon technologies improving so fast, does it sometimes make sense to wait to invest in new infrastructure?

It can make sense to wait for low-carbon technology to improve in efficiency and cost, but to slow climate change we must balance what ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

What does the COVID-19 pandemic mean for climate change?

While the short-term effects of the Covid-19 shutdown have been to lower greenhouse gas emissions, we are on the verge of losing ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago
Land Use & Freshwater

Freshwater and Climate Change

Climate change affects both the quantity and quality of the limited amount of freshwater on Earth and threatens the availability of ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Fertilizer and Climate Change

Human-made fertilizers have greatly boosted crop production, letting farmers grow more food on less land. But this uptick in fertilizer ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Food Systems and Agriculture

Agriculture is likely to face severe impacts from climate change. At the same time, the production, storage, and transport of food ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Why aren't we looking at more hydropower?

Hydropower is already a major source of power globally—it’s the largest source of renewable electricity and one of the fastest growing ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Biofuel

Biofuel is any liquid fuel made from “biomass”—that is, plants and other biological matter like animal waste and leftover cooking fat ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Soil-Based Carbon Sequestration

Soil-based carbon sequestration is a way to remove CO2 from the air and store it somewhere it can’t easily escape: in soils, which store ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago

Why aren't biofuels more prevalent?

Without new breakthroughs, producing much more biofuel than we do today might be a net-negative for the climate—and would definitely ...
MIT Climate Portal avatar
Written by MIT Climate Portal
Updated over a week ago