50 FAQs on Global Warming

In this article we answer 50 FAQs concerning our climate crisis. They cover the causes of global warming, the greenhouse effect, the impact of climate change on polar regions, climate tipping points, Earth's temperature, methane emissions from livestock, renewable energy sources, and air pollution from fossil fuels. We also look at the effects of global warming on animals and the biosphere.
Heavy rainfall in city, climate change
Rising temperatures generally make wet regions wetter and dry regions drier. Photo: © Genaro Servin/Pexels.com

Here are 50 of our most popular FAQs about global warming, covering its causes and effects, its links with deforestation, as well as its impact on the oceans. We also include questions and answers on the greenhouse effect and greenhouse gases, along with FAQs on energy and fossil fuels. For more FAQs, please see: 50 Frequently Asked Questions on Climate Change.


FAQs on the Causes of Global Warming

Q. Why is today’s climate change so different?

Answer: There are two reasons why the current climate crisis is unique.

First, – as explained in a recent paper published in Nature – because in contrast to all other fluctuations, today’s climate change is a worldwide event affecting 98 percent of the planet. None of the earlier climatic events occurred on a global scale. Any significant peaks or troughs in temperature occurred in less than half the globe at any one time. 1

Second, whereas all previous fluctuations occurred as a result of volcanic activity, today’s warming is caused by man-made emissions of greenhouse gases warming up the atmosphere. 2

Q. What is the No 1 cause of global warming?

Answer: Global warming is unambiguously caused by the burning of fossil fuels in power plants, industrial furnaces, motor engines and heating systems. (Source: IPCC Fifth Assessment 2013.) But see also our article on: What’s the Root Cause of Climate Change?

Q. Is solar energy a cause?

Answer: No. The amount of energy received by the Earth from the sun has shown no net increase since the 1950s. On the contrary, satellite data shows that total solar energy has declined slightly in the past 40 years or so, while the Earth has warmed. Over the same period, mean global temperature has risen considerably. It is therefore impossible for solar power to have caused the global warming trend over the past half-century. Source: NASA

Graph showing temperature of Earth vs solar activity
Temperature vs Solar Activity. Image: © NASA-JPL/Caltech

Q. How many scientists think global warming is real?

Answer: A massive 97 percent of active climate scientists believe that global warming is happening and that humans are the cause.

Virtually all active climate scientists (97–98 percent) who publish studies, support the consensus on man-made climate change, while the remaining 3 percent of studies either cannot be replicated or contain significant errors.

In addition, the contrarian studies (the 3 percent) are written by researchers whose climate expertise and scientific prominence are markedly below that of the others. 3 4 For more on this issue, please see: Climate Change Denial.

Q. Is the greenhouse effect natural?

Answer: Yes. The greenhouse effect is quite natural, and life on Earth depends upon it. Solar energy arriving from the sun in the form of sunlight, passes through the atmosphere and strikes the surface of the planet. As a result, the Earth’s land surface becomes warm and gives off heat in the form of infrared radiation. This radiation rises into the atmosphere, where some of it is trapped by naturally occurring “greenhouse gases” (GHGs) and radiated back to Earth, keeping the planet at a cosy average temperature of 15°C (59°F), instead of the chilly minus 18°C (0 °F) it would otherwise be. Natural greenhouse gases include water vapor, carbon dioxide, methane and nitrous oxide, and it is these GHGs that together create the greenhouse effect.

Q. If the greenhouse effect is natural, why is it causing global warming?

Answer: Because human activities are causing greenhouse gas levels to increase. In fact, humans are releasing such vast quantities of GHGs into the atmosphere that Earth’s climate system has been overwhelmed. The new supercharged greenhouse effect is completely man-made and lies at the heart of global warming.

The extra greenhouse gas released into the troposphere (lower atmosphere) comes mainly from the burning of fossil fuels (coal, petroleum, natural gas) in power plants, industrial furnaces and factories, as well as in engines (in cars, ships, planes). and domestic heating systems.

Q. If global warming disappeared, what would our climate be like?

Answer: Left to itself, Planet Earth would experience a slight cooling. But as we have just seen, man-made greenhouse gases have changed the natural order completely and propelled the world towards rapid warming.

Q. Are the rich to blame for global warming?

Answer: According to a new analysis by The Guardian, based on data from German non-profit Atmosfair, a return flight from London to New York (economy class) generates about 1 tonne (1,000 kg) of CO2 emissions. 5

BBC News – using data from the Department for Business, Energy and Industrial Strategy (BEIS) – states that carbon emissions per passenger on long haul flights are about three times higher for business class and four times higher for first class. So, the same flight costs 3 tonnes of CO2 for business class passengers and 4 tonnes for those in first class.

Leaving aside the fact that 70 percent of flights out of the UK are booked by only 15 percent of the population 6 , a first-class passenger who takes a return flight from London to New York, generates more heat-trapping carbon dioxide emissions than citizens of most countries produce in a whole year.

FAQs About the Effects of Global Warming

Q. What evidence proves global warming is real?

Answer: Back in 2009, the U.S. National Oceanic and Atmospheric Administration (NOAA) identified 10 unmistakable signs of global warming based on satellite observations and other datasets. 7

Since then, countless scientific studies have confirmed that climate change causes – inter alia – (1) higher temperatures in the troposphere; (2) melting of the world’s glaciers and ice sheets; (3) ocean acidification; (4) more intense heatwaves on land and sea; (5) ocean deoxygenation; (6) sea level rise; (7) longer and more intense droughts; (8) increasing humidity; (9) the spread of diseases like malaria; (10) a growing loss of biodiversity.

Q. Is climate change making the Arctic hotter?

Answer: Yes. Climate change is affecting the Arctic more than anywhere else. Temperatures in the region haven’t been as high for at least 44,000 years, and perhaps as long as 120,000 years. 8 For more, see: Why Are Arctic Fires So Dangerous?

Q. Does global warming lead to higher rainfall?

Answer: Yes. Higher temperatures lead to a more active water cycle, which results in greater and more rapid evaporation and precipitation, as well as more extreme weather events.

Q. How many animals died in the 2019/20 Australian bushfires?

Answer: According to Professor Chris Dickman, a fellow of the Australian Academy of Science, as many as one billion animals died in the Australian bushfires (2019-2020). An estimated one third of all koala bears perished, including 20,000 koalas in a single reservation. 9

Q. If temperatures rise by more than 1.5°C how many animals face extinction?

Answer: If temperatures exceed 1.5°C, one in six species will be at risk. However, if they exceed 2°C, the loss of biodiversity will be significantly greater. (Source: WWF) For more on this, see: Why Does Half A Degree Rise in Temperature Make Such a Difference to The Planet?

Q. What is a climate tipping point?

Answer: To understand what a tipping point is, imagine a massive lumberjack armed with an axe is trying to chop down a huge tree. He chops away for hours and hours, until finally he senses that the tree is about to fall. If he hits it once more, he knows it will keel over and fall to the ground. This is the tipping point. Once he crosses it, the tree will start to fall and nothing will stop it.

In the same way, climate tipping points are critical thresholds that, if crossed, are likely to lead to an irreversible change in the climate, which nothing can stop.

A good example is ice-melt in West Antarctica, where the thinning and/or collapse of the ice shelves could trigger a rapid and irreversible loss of land ice into the ocean – which would add significantly to sea levels. For more details, see: Sea Level Rise: Facts & Information.

The problem about climate tipping points, in particular, is that they make take time to appear. In fact, we may have already crossed one without realizing it. Which is why we need to act to reduce carbon emissions as soon as possible.

Q. What are the most dangerous climate tipping points?

Here are the 7 most dangerous climate tipping points that scientists are worried about.

  1. Collapse of the West Antarctic Ice Sheet
  2. Drying Out of the Amazon Rainforest
  3. Slowdown of the Atlantic Meridional Overturning Circulation (AMOC)
  4. Thawing of Northern Permafrost
  5. Collapse of the Greenland Ice Sheet
  6. Ecological Shifts in the Northern Boreal Forests
  7. Loss of Tropical Coral Reefs

Q. Will global warming destroy the planet?

Answer: If left unchecked, climate change will almost certainly lead to runaway global warming, which will probably destroy the biosphere even if the planet itself survives. So, the ultimate outcome is not really in doubt.

However, the key question is “how long might this process take?” In other words, if we do nothing much until the climate becomes clearly damaging to our health, in (say) 30-40 years, is there still time to save the situation? Answer: no one knows.

Unfortunately, by the time the situation does become clearer, it may be too late to do anything about it. Maybe the West Antarctic ice sheet has begun an irreversible meltdown. Maybe new diseases have migrated from the tropics due to global warming. Maybe a runaway permafrost-thaw has increased temperatures beyond the tolerance of most plants and/or phytoplankton.

Frankly, nothing is certain. But one thing is almost certain: if we don’t start taking climate change more seriously, we are going to regret it. Because it will be more difficult and more painful, and a lot more expensive to tackle it in 20 years’ time.

Q. How does climate change affect animals?

Answer: Global warming affects terrestrial animals and birds in a wide variety of ways. The main impacts include: severe weather events (heat waves, droughts, hurricanes, and melting sea ice), and changes to life cycle events (phenology).

Rising temperatures impact directly on the animals themselves, their habitats and the biomes within which they are found. It can lead to heat stress; reduction in the water supply (rivers, ponds); loss of plant food; loss of prey; forest fires; and an increase in malarial breeding grounds.

Effects of Climate Change on Animals
10 Endangered Animals
10 Endangered Birds of Prey
10 Birds Threatened by Climate Change

For example, melting sea ice adversely affects the availability of food for polar bears. Increased snowfall in northern latitudes makes it harder for elk to find food. Increasing Arctic temperatures have led to an explosion in the numbers of mosquitos, botflies and warble flies that plague caribou herds migrating northwards from the USA. 10

Seabirds are having difficulty finding prey (like sardines, squids) because they can’t adapt their biological rhythms to temperature changes in the ocean. 11

FAQs About the Temperature of the Planet

Q. How much has Earth’s temperature increased?

Answer: Earth’s temperature has increased by 1.15°C since the benchmark period 1850-1900. And the rate of temperature change is increasing: the global annual temperature has increased at an average rate of 0.07°C (0.13°F) per decade since 1880 and over twice that rate (+0.18°C / +0.32°F) since 1981. 12

At the current rate of warming, Earth will reach the 1.5°C threshold between 2030 and 2052. (Source: Climate Central. October 9, 2018.)

Q. Is it true that 19 of the 20 hottest years have occurred since 2001?

Answer: Yes. Nineteen of the 20 warmest years all have occurred since 2001 (Source: NASA/GISS)

The five warmest years during the period 1880–2019 have all occurred since 2015, while nine of the 10 warmest years have occurred since 2005.

Note also, that between 1900 and 1980 a new temperature record was recorded on average every 13.5 years. Since then, temperature records have occurred every 3 years. 13 For more, see: Global Temperature Projections.

Global Warming FAQS: How Temperatures Are Increasing: Official Data
Global land and ocean surface temperature for January 2020 was the highest in the 141-year record, with temperatures 1.14°C (2.05°F) above the 20th century average. Source: NOAA

Q. If there was no greenhouse effect what would Earth’s temperature be?

Answer: minus 18°C (0°F). The greenhouse effect is what makes the planet habitable. Without it, Earth’s would have an average temperature of -18 °C and be covered in ice. 14

Q. Was Earth ever warmer in the past?

Answer: Yes, temperatures have been higher in the past, although you would have to go back more than 3 million years to find a period that was clearly warmer than today.

Earth’s hottest periods (the Hadean, the late Neoproterozoic, the Paleocene-Eocene Thermal Maximum) occurred millions of years before humans existed. Those paleoclimates were nothing like our climate. What’s more, the increases in temperature which occurred then, unfolded over much longer periods than today’s warming.

Modern human civilization, with its permanent agriculture-based settlement, has only developed over the last 10,000 years or so. This period has been one of low temperatures and relative climate stability.

FAQs About Greenhouse Gases (GHGs)

Q. How much have CO2 levels increased since the Industrial Revolution?

Answer: Carbon dioxide in the atmosphere has risen by 43 percent since 1780. By comparison, during the 10,000 years prior to the Industrial Revolution, carbon dioxide levels rose less than 1 percent.

Q. Which is the most powerful greenhouse gas over 100 years?

A. Carbon dioxide (CO2)
B. Methane (CH4)
C. Nitrous Oxide (N2O)
D. Sulfur hexafluoride (SF6)

Answer: Sulfur hexafluoride (SF6), one of the family of F-gases, is the most powerful greenhouse gas with the highest global warming potential (GWP). (Source: U.S. EPA)

Global Warming Potential Over 100 Years

Greenhouse GasGWP
Carbon Dioxide (CO2)1
Methane (CH4)28
Nitrous Oxide (N2O)265
Fluoroform (HFC-23)12,400
Sulfur hexafluoride (SF6)23,500
Source: GHG Management Institute.

Q. Which greenhouse gas is emitted by cows?

A. Methane
B. Sulfur dioxide
C. Carbon monoxide
D. Sulphur hexafluoride

Answer: Methane is emitted by cows and other ruminants.

Cattle and other ruminants are significant emitters of methane heat-trapping gas, which is produced by microorganisms (known as methanogens) in their digestive system. They contribute roughly 38 percent of all methane emissions: or 62 percent of man-made emissions. (Source: Global Methane Budget 2000-2017 (Supplemental Data). Global Carbon Project 2019) For more, see: Why Are Methane Levels Rising?

Q. Do trees absorb more CO2 than they respire?

Answer: Yes. During the daytime, every tree takes in carbon dioxide from the air during photosynthesis, and emits oxygen in the process. But during the day and night it gives off CO2 in a process known as respiration. Fortunately, it takes in much more CO2 when photosynthesizing, than it respires. 15

Q. Which country emits the most CO2: USA, Russia, China or India?

Answer: China is the largest single producer of CO2 emissions, accounting for roughly 9,838.8 million metric tons, annually. Next comes the United States, which produces 5,269.5 million metric tons. India is some way back, with 2,466.8 million metric tons of CO2. 16

Q. Which country has the biggest carbon footprint, per person: USA, Japan, China, or Australia?

Answer: Australia has the world’s biggest carbon footprint per capita.

Carbon Footprint per Capita (2019)CO2 metric tons
United States16.1
Source: Emissions Database for Global Atmospheric Research (EDGAR) (2019)

Q. How many carbon emissions are YOU responsible for?

To find out, use our Carbon Footprint Calculator.

Q. Which country has emitted the most CO2 during the past 200 years: China, USA, Russia, or the EU?

Answer: The United States. In fact, The U.S. has emitted twice as much CO2 as, for example, China. This is significant because GHGs have a long active life in the atmosphere. CO2 in the atmosphere lasts for 200-1,000 years, and about 20 percent may linger for 1,000 years or longer. 17

Q. Once emitted, how long does CO2 remain active?

Answer: Studies suggest that roughly 50 percent of CO2 emitted into the atmosphere returns to earth within the first 50 years, about 70 percent in the first 100 years, and 80 percent within 300 years. The remaining CO2 remains in the atmosphere for up to 1,000 years, or more.

Which is why switching to emission-free renewable energy as quickly as possible, is so important. Because even after we stop using fossil fuels, evidence indicates that the Earth may continue to warm for hundreds, perhaps thousands of years. 18 19

FAQs About Global Warming, Energy & Fuels

Q. Which of these energy sources is not renewable?

A. Nuclear
B. Solar
C. Hydroelectric
D. Geothermal
E. Wind
F. Biomass

Answer: Nuclear energy is not a renewable energy source. But Nuclear fusion may be, although we won’t know for decades.

Renewable energy is energy that can regenerate and can replenish itself indefinitely. The five most common renewables are solar energy, organic biomass and biofuels, hydropower, offshore and onshore wind power, as well as geothermal energy from subterranean heat sources. Next generation renewables include tidal power and wave energy, as well as hydrogen power. Nuclear fusion remains futuristic.

All power stations turn heat into electricity using steam. In nuclear plants, the heat is created when atoms split apart – a process called fission. The fission releases energy in the form of heat and neutrons. The released neutrons then go on to hit other neutrons and repeat the process, hence generating more heat. In most cases the fuel used for nuclear fission is uranium, which is a finite resource, unlike solar or wind. To be counted as renewable, the energy source should be sustainable for an indefinite period of time. 20

Q. Which of the following is not a fossil fuel?

A. Coal
B. Natural Gas
C. Oil
D. Wood

Answer: Wood is not a fossil fuel. Fossil fuels are formed from the fossilized, buried remains of plants and animals. Typically, they have been buried for millions of years. Unlike, coal, gas and oil, wood has never been buried and fossilized.

Q. Which fossil fuel emits the most CO2?

A. Coal
B. Natural Gas
C. Petrol
D. Propane (Calor Gas)

Answer: Coal emits the most CO2 emissions.

Fuel TypeCO2 Emissions per million
British Thermal Units (Btu)
Coal (bituminous)205.7
Diesel/heating oil161.3
Propane (Calor Gas)139.0
Natural gas117.0
Source: U.S. Energy Information Administration

Q. Which electricity source has the lowest life-cycle CO2 emissions?

A. Biomass
B. Solar
C. Geothermal
D. Hydro
E. Nuclear
F. Wind

Answer: Wind has the lowest life-cycle CO2 emissions.

Life Cycle CO2-e Emissions from Selected Electricity Power Sources

Power SourceMedian (gCO2eq/kWh) Values
Solar PV48
Wind (onshore)11
Source: IPCC Working Group III – Mitigation of Climate Change, Annex II Metrics and Methodology – A.II.9.3 (Lifecycle greenhouse gas emissions) (PDF) IPCC Fifth Assessment Report (2013) pp. 1306–1308.

Note: A recent study indicates that the construction of solar, wind or nuclear power plants results in an insignificant carbon footprint compared with savings from avoiding fossil fuels. 21

Q. How much US energy consumption comes from renewable sources?

A. 11 percent
B. 17 percent
C. 21 percent
D. 31 percent

Answer: In 2019, renewable energy sources accounted for about 11 percent of total U.S. energy consumption and about 17 percent of electricity generation. (Source: U.S. Energy Information Administration)

Q. Which renewable energy is used most in America?

A. Geothermal
B. Wind
C. Solar
D. Hydroelectric
E. Biomass

Answer: Biomass. In 2019, renewable energy sources accounted for about 11 percent of total U.S. energy consumption. The breakdown is as shown below.

Global Warming FAQs: How Much Renewable Energy Do Americans Use?

Q. What is Hydrogen Power?

Hydrogen energy comes from hydrogen gas (H2). The most exciting production method is through electrolysis, powered by electricity from renewables like solar and wind power. The resulting “green hydrogen” can be used to decarbonize difficult sectors of our energy system (such as transportation, heating and industry), as well as serving as storage for intermittent energies.

Q. What is Sustainable Energy?

Sustainable energy can be defined as: energy which is generated and used in such a way that it meets the needs of the present without affecting the ability of future generations to meet their own needs. For the full story, see: Sustainable Energy Explained.

FAQs About the Impact of Global warming on Oceans

Q. What percentage of global warming is absorbed by the Ocean?

A. 25 percent
B. 50 percent
C. 66 percent
D. 93 percent

Answer: The ocean absorbs 93 percent of the heat generated by global warming. Recent studies estimate that warming of the upper oceans accounts for about 63 percent of the total increase in the amount of stored heat in the climate system from 1971 to 2010, and warming from 700 meters down to the ocean floor adds about another 30 percent. 22 For more, see: How Do Oceans Influence Climate Change?

Q. Does climate change harm phytoplankton?

Answer: Without phytoplankton, human life on Earth would not be possible. Unfortunately, since 1950, the number of phytoplankton in the ocean has decreased by around 40 percent under pressure from global warming. 23 24 25 Which is bad news, because these sea plants are estimated to produce between 50 to 85 percent of the oxygen in Earth’s atmosphere. 26

Zooplankton and the Marine Food Chain
Marine Food Web
Krill At Risk from Climate Change

Q. What is the main cause of coral bleaching?

Answer: Ocean warming is the leading cause of coral bleaching. When the sea gets too warm, corals expel the symbiotic algae (zooxanthellae) which lives in their tissues, causing the coral to turn completely white. This coral bleaching is not necessarily fatal, but it is highly stressful and does result in higher mortality levels. Survival is much more likely if water temperatures return to normal quickly.” 27 For more details, see: Coral Reefs are Dying From Climate Change.

Q. Are ocean storms caused by global warming?

Answer: Yes. Scientific evidence indicates that the frequency and severity of extreme weather events in the ocean – such as hurricanes, cyclones and typhoons – are exacerbated by climate change.

A recent study which conducted simulations of 15 tropical storms in the Atlantic, Indian and Pacific Oceans found that warming in the ocean and atmosphere boosted rainfall by 5-10 percent, although wind speeds were largely unchanged.

But things will get worse if global warming intensifies. Researchers say that if global temperatures increase by 3-4°C this century then hurricane rainfall could increase by 33 percent, and wind speeds could increase by as much as 25 knots. 28 For more, please see: Effects of Global Warming on Oceans.

Q. What is El Niño? Is it linked to climate change?

El Niño is one of the phases of the El Niño-Southern Oscillation (ENSO) regional weather cycle in the equatorial Pacific Ocean. An El Niño event is associated with drought-like conditions in SE Asia and Australia, warm dry weather in Central America and in the Amazon Basin, but much wetter conditions along the coasts of northern Peru and Ecuador and across Argentina, Uruguay and Paraguay.

The opposing phase of ENSO is La Niña, whose effects are almost the reverse. For details, see El Niño-Southern Oscillation (ENSO).

The mechanisms behind El Niño and La Niña are not directly affected by global warming, though the intensity and frequency of their effects are. Another similar weather cycle is the Indian Ocean Dipole (IOD), which can reinforce both El Niño and La Niña phases. The travelling Madden-Julian Oscillation (MJO) is another Indo-Pacific weather cycle, although its effects are genuinely global.

What happens if the Antarctic ice sheet melts?

Answer: This is the ultimate doomsday scenario. Because if the Antarctic ice sheet does melt, most coastal cities will be submerged, along with all river deltas and low-lying coastlines. The Netherlands will be underwater, as will the east coast of China and the UK. Major population centers such as Osaka, Shanghai, Bangkok, Manila, Jakarta, Dhaka, Alexandria, London, Amsterdam, New York, Houston, Atlantic City, Charleston, Florida, Rio de Janeiro (among many others) will be uninhabitable. Hundreds of millions of people will be made destitute and homeless. Some countries may even collapse.

But is the Antarctic ice sheet likely to melt? No. At least not for several centuries. So, relax, nothing is going to happen overnight.

Both polar regions are experiencing considerable ice melt. Arctic sea ice is close to a record low, and many glaciers on the Greenland ice sheet are retreating fast. In the Southern Ocean, Antarctica is colder and much bigger, and its two ice sheets are several kilometers thick. But scientists worry about Thwaites glacier in West Antarctica – it is seen as unstable and vulnerable to premature melting. But even this might take several decades.

The circumpolar Arctic region and the Antarctic continent are probably the two areas of greatest concern to climate scientists, for the simple reason that they guard the world’s largest reserves of permafrost carbon and freshwater. Either of these regions, if their ice melted, could deal the planet’s climate system a devastating blow. But it’s not going to happen overnight.

NOTE: Greenland holds the sea level equivalent of 7 meters (24 ft), while Antarctica holds 58 meters (190 ft) worth of sea level rise.

FAQs About Deforestation and Global Warming

Q. Is Deforestation the second leading cause of global warming?

Answer: Yes. Land use changes, notably deforestation, represent the second largest anthropogenic source of CO2 emissions, after fossil fuel combustion. 29

Total CO2 emissions for the year 2019 amounted to 59.1 GtCO2e (billion tons of CO2 equivalent). Of this, 6.8 GtCO2 (roughly 11.5 percent) was from deforestation and land use change. (Source: UN Emissions Gap Report 2020.)

Q. How much rainforest has been lost since 1950?

A. About a quarter.
B. About a third.
B. About half.

Answer: About half. Half of the forests that originally covered 48 percent of the Earth’s land surface have been cut down. Only one-fifth of the Earth’s original forests remain pristine and undisturbed. 30 Rain forests that once grew over 14 percent of the land on Earth now cover only about 6 percent, due to the human demand for wood and arable land. 31 For more, see: History of Deforestation.

Q. Why are rainforests so important to the Biosphere?

A. They contain an extremely wide range of animals, birds, insects and plants.
B. The chemical blueprint for aspirin (and many other drugs) comes from rainforest plants.
C. They create their own water cycle benefiting the entire region.
D. They absorb a significant amount of carbon dioxide from the atmosphere.
E. All of the above.

Answer: All of the above. Rainforests benefit the planet in a host of different ways. From an ecological viewpoint, they are irreplaceable.

For more details, see: The Amazon Rainforest and also Deforestation in the Amazon Rainforest.

FAQs About Pollution

Q. Are electric vehicles zero-emission?

No. When driven, electric vehicles (EVs) produce zero pollution and, if recharged using clean electricity (from renewable sources), they produce no greenhouse gases. However, the car and its battery still needs to be manufactured, and this process does involve emissions.

Q. Do aerosols have a cooling effect?

Answer: Yes. Bright-colored or translucent particles of air pollution in the atmosphere (from sulfates and nitrates, for example, or salt) can have a cooling effect on the planet by reflecting solar radiation back into space. For example, following the 1991 eruption of Mount Pinatubo, global temperatures dipped by about a half-degree (0.6°C) for about 2 years. For more about the cooling effect of airborne pollutants, see: Asian Brown Cloud: Toxic Haze.

By contrast, black carbon aerosols absorb radiation, thus warming the atmosphere, but at the same time they shade the surface from sunlight thus exerting a cooling effect. Organic carbon, (brown carbon) from wood-burning, for example, tends to have an overall warming influence. For more details, see: How Do Aerosols Affect Global Warming?

Aerosols created by the incomplete combustion of petroleum or diesel in vehicle engines react with other gases to produce ground level ozone which also warms the atmosphere, causing a wide range of harmful respiratory effects in humans. See: Health Effects of Air Pollution.

Q. How many sea creatures choke on plastic waste?

Answer: Every year, we produce between 275 and 350 million metric tons of plastic waste, of which 100 million tons is mismanaged, with about 90 percent ending up in the ocean – that’s 90 million tons of plastic, including 5 trillion pieces of microplastic. Even worse, these microplastics have been found to block the digestive tracts of at least 267 different species. 32 Scientists calculate that plastic waste kills an estimated 1 million sea birds and 100,000 sea mammals, turtles and fish, annually. Plastic remains in our hydrosphere for decades, damaging or killing thousands of sea creatures every day. (Source: UN Facts About Oceans.)

Now we too are consuming microplastics – from tap water. According to a 2017 global study, an average of 83 percent of global tap water samples were found to be contaminated by micro plastic pollutants. America leads the field with a 94 percent rate of contamination. European countries, have the lowest contamination rate (72 percent). The study shows that people may be ingesting between 3,000 and 4,000 microparticles of plastic from tap water per year. 33

FAQs on Climate Action to Mitigate Global Warming

Q. Will COVID-19 make the world greener?

Answer: Will the social changes imposed by the coronavirus help us to adopt a new attitude to climate change? Will Covid-19 persuade governments to unite behind an effective climate change mitigation strategy?

It’s possible. After all, a worldwide pandemic can’t be dealt with by scientists from just one nation: it takes a global effort. Billions of medical items need to be manufactured; research laboratories need to find a vaccine. Scientists need to match existing technologies to mitigate the spread of infection – like ionisers – or invent completely new ones. Virologists need to advise governments how to contain and track the virus; social workers are needed to trace and test those who may be infected; and front-line health workers are needed to care for those who are.

Above all, information needs to be shared, along with other resources, because today’s outbreak in one country could become tomorrow’s outbreak in another. There’s no escape. Rather like global warming.

The point is, our climate crisis – even more than Covid-19 – necessitates a unified approach by (at least) the governments of major nations. But as long as these wealthy nations continue to avoid taking responsibility for their high carbon footprint, especially their high per capita footprint, no collective action seems likely.

On the other hand, popular support for a greener, more sustainable world, seems to be growing. Will this support survive the predicted recession with its inevitable financial squeeze and loss of jobs, or will it lead to a split between the haves (pro-green, pro-renewable energy) and the have-nots (pro-jobs)? The answer may hinge on the answers to three other questions: (a) Can the wealthier governments persuade their taxpayers to pay for the huge costs of climate action? (b) Can the United Nations become a unifying force – one that is able to set the agenda and mediate between the parties? (c) Can the technology be found to connect renewable energy sources to the electricity grid, to provide longer-lasting batteries for electric vehicles (EVs), and to capture and store carbon emissions? For more. see: Effect of COVID-19 on Climate Change?

Q. Is it too late to prevent climate change?

Answer: We can’t turn back the clock and reverse all the effects of global warming that we’ve caused. But it’s not too late to limit the worst effects of climate change that are on the horizon. In order to do this, we need to follow a 2-step plan.

First, we need to drastically reduce our carbon emissions from the burning of fossil fuels, like coal, oil and natural gas and switch to cleaner, more sustainable forms of energy, like solar, wind, hydroelectric, geothermal and biomass. This step is referred to as ‘climate change mitigation‘.

Secondly, we must adapt our cities, our infrastructure, our coastlines and our economies to cope with the effects of climate change that we cannot avoid. Creating ‘sponge cities‘ (e.g. Wuhan, China) – designed to withstand increased rainfall – is an interesting example of this type of ‘climate change adaptation‘.

Of course, the key issue is whether we can successfully transition from a world powered by fossil fuels, to one powered by renewable energies. Timing is another issue. Unfortunately, we don’t know how long we have before we reach a tipping point of no return.

For a less optimistic viewpoint, see: Our Climate Plan Can’t Cope.

Q. What are climate ethics?

The ethics of climate change are concerned with the equity and justice of our climate crisis. In particular, it deals with questions like: Who is responsible for global warming? Who should pay the costs of it? Should the needs of animals be taken into account? and so on.

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Take The Test!


Q. What can I do about climate change?

Answer: The best thing you can do is to sell your car and buy a bicycle. Being a fossil-fuel car-driver is really not good for the planet. Unfortunately, for a great many people, giving up driving is simply not feasible. So here are some other options, listed in descending order of value:

  • Swap your diesel/petrol car for an electric vehicle powered by renewable electricity.
  • Stop flying. (An economy class return from London to New York generates 1 metric ton of CO2 emissions.)
  • Reduce the number of flights you take.
  • At home, switch to an electrical heating system powered by renewable electricity.
  • Try to make do with fewer material possessions. (1 house, 1 car, 1 TV, 1 computer, and so on.)

Don’t waste time and money ‘offsetting’ your emissions. It’s not really ethical and some carbon offset schemes pay less than 30 percent to the projects they claim to support.

Speaking up about the need to switch from fossil fuels to renewables is also extremely important, but taking action always gives us a sharper sense of personal involvement. For more details, see: How to Reduce Your Carbon Footprint?

NOTE: If you have any suggestions for additions to our Global Warming FAQs, please contact us. See details at the bottom of the page.

Q. How bad will global warming get?

Answer: If the world takes no effective climate action, the IPCC predicts a rise in global temperature of between 4.8 and 5.7 degrees Celsius by 2100. This is the worst-case scenario (RCP 8.5), which appeared in the IPCC’s Fifth Assessment Report (2014).

In this scenario, all Arctic polar ice has disappeared and the Antarctic ice sheet is dwindling. Rainforests have been turned into dry grassland. With many tropical zones now scorched and almost uninhabitable, Canada and Siberia now represent the most desirable real estate on the planet.

Meantime, sea levels are still rising. In America, much of Florida is now under water, while the Gulf Coast and the entire Atlantic seaboard is submerged. In Europe, London and the entire east coast of England up to Newcastle is submerged. The Netherlands has disappeared, so too has Denmark as well as Riga, Tallinn, Stockholm, Helsinki, most of the Baltic coastline and the lowlands of northern Germany. Venice, Trieste and Verona are also underwater. In China, Shanghai has disappeared and there is now nothing but sea between Beijing, Wuhan and where Shanghai used to be. Hong Kong has disappeared too, as have Phnom Penh, Ho Chi Minh City, Singapore, Bangkok, Dhaka, and Mumbai.

World stock markets, commodity exchanges, 5G networks, internet, cloud computing, mobile phones, laptops, online trading systems and paper currencies have long since collapsed, leaving power in the hands of competing mini-states, powered by whatever fossil fuels are available. Globally, life has become a continuous quest for food and security with continuous waves of climate refugees invading the continental uplands in search of shelter, battling with indigenous populations who see them as intruders. This is a nightmare situation to be avoided at all costs.

Q. What are governments doing about global warming?

At present, governments meet annually at meetings of the United Nations Framework Convention on Climate Change (UNFCCC) – the so-called COP conferences – as part of an ongoing process to update their commitments under the Paris Climate Agreement.

However, progress on agreeing substantial emission reductions has been painfully slow. As a result, we have no internationally agreed climate plan that is fit for purpose. For the history and timeline of negotiations about global warming, see: UN Climate Talks/Timeline.

If you found our Global Warming FAQs useful, and would like a short overview of what’s happening to the planet, please see: Climate Change Essay in 1,000 words.

Alternatively, see: Climate Change for Beginners, or read our article: Climate Change for Students.


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