Questions & Answers on Climate Change
What are greenhouse gases and how do they affect the climate system?
Carbon dioxide is one of several greenhouse gases. The other main ones are water vapour, methane, and nitrous oxide. Together, these greenhouse gases create the greenhouse effect – a natural atmospheric process that keeps the Earth’s surface at a temperature comfortable for humans and other life to exist. The natural greenhouse effect keeps the surface of our planet at a habitable temperature, about 33 °C higher than it would be without an atmosphere.
What is the difference between weather and climate?
"Weather" refers to the day-to-day state of the atmosphere such as the combination of temperature, humidity, rainfall, wind, and other factors. "Climate" describes the weather of a place averaged over a period of time. Climate is something that can be expected to happen in general, like a cold winter season, whereas weather is what a person might experience on any given day.
What is the difference between global warming and climate change?
The terms "global warming" and "climate change" are sometimes used interchangeably, but global warming is just one of the ways in which climate is affected by rising concentrations of greenhouse gases. "Global warming" describes the recent rise in the global average temperature near the earth's surface, which is caused mostly by increasing concentrations of greenhouse gases (such as carbon dioxide and methane) in the atmosphere from human activities such as burning fossil fuels for energy.
Is it climate change, global warming, or global climate crisis?
Each of these terms refers to the same thing—the fact that the average temperature of the earth's atmosphere is rising. As the temperature rises, various impacts are changing aspects of our climate—hotter summers, rising ocean temperatures, melting polar ice, increased storm activity. These go beyond mere changes in the weather. As these impacts grow in frequency and severity, they will—and in many cases already have—create crises for people and nature around the world. If unchecked, these impacts will spread and worsen with more animal extinction and biodiversity loss, water shortages, and displaced communities.
Is there scientific consensus that people are causing today’s climate change?
Yes. The Intergovernmental Panel on Climate Change's Sixth Assessment Report which represents the work of hundreds of leading experts in climate science, states that "it is unequivocal that human influence has warmed the atmosphere, ocean and land. Widespread and rapid changes in the atmosphere, ocean, cryosphere, and biosphere have occurred.”
What are the main threats 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.
Who is most at risk from the impacts of climate change?
Everyone will be affected by climate change, but some people may be more affected than others. Among the most vulnerable people are those in overburdened, underserved, and economically distressed communities. People with less access to healthcare, adequate housing, and financial resources are less likely to rebound from climate disasters.
How fast is the climate changing?
The Earth’s climate has always changed naturally. Usually, these changes take place over thousands of years, such as the coming and going of ice ages. But the climate is now changing much faster due to changes to the atmosphere caused by human activities. Burning fossil fuels releases greenhouse gases that enhance the Earth’s natural greenhouse effect, causing warming. Evidence from air trapped in ice cores shows that the current rate of warming is occurring at a faster rate than has occurred in thousands of years. Recent warming has occurred about 10 times faster than warming at the end of an ice age. The increase of carbon dioxide due to human activities is occurring more than 250 times faster than at the end of the last Ice Age.
How much time do we have to stop climate change?
There is no definitive line of demarcation that we can protect against, instead it is a matter of minimizing the effects of climate change. Every day that goes by, we are releasing carbon into the atmosphere and increasing our planetary risk. Most scientists agree that we need to immediately reduce carbon emissions to give our planet and our population the future that is least impacted.
What is a Climate Emergency?
Politically, to declare a 'Climate Emergency' is an acknowledgement of this crisis. It would mean immediately prioritising action across government to end support for fossil fuels, invest in the clean economy and restore nature at home and abroad.
What are the benefits of taking action now?
The longer people wait to act on climate change, the more damaging its effects will become on the planet and people’s health. If people fail to take action soon, then more drastic and costly measures to prevent greenhouse gases from exceeding dangerous levels could be needed later.
How is climate change affecting animals?
Changing climates directly and indirectly cause stress to animals across the world. Many species are approaching—or have already reached—the limit of where they can go to find hospitable climates. In the polar regions, animals like polar bears that live on polar ice are now struggling to survive as that ice melts
How is climate change affecting the ocean?
Warming ocean temperatures are melting polar ice, shifting ocean currents and fish migrations, and leading to coral bleaching and die off. Because of oceans’ important role in regulating Earth’s climate by absorbing greenhouse gas emissions, they are taking a direct hit from climate change. All this extra absorbed carbon dioxide is altering the chemistry of our oceans, making them more acidic. In fact, the rate of ocean acidification is the highest it has been in 300 million years! This negatively impacts lots of marine habitats and animals, but is a particular threat to shellfish who struggle to grow shells as water becomes more acidic.
How is climate change affecting farms and our food?
Climate change is disrupting weather patterns, leading to more extreme and frequent droughts and flooding events that directly threaten harvests. The warming climate is contributing to rising populations of insect pests that eat a higher share of crop yields.
Does deforestation contribute to climate change?
Yes, deforestation contributes to climate change in a couple of ways. Forests are one of our most important types of natural carbon storage, so when forests get cut down, they lose their ability to store the greenhouse gas. Burning trees release even more carbon into the atmosphere. Forests are some of the best "natural climate solutions" we have on this planet. If we can slow or stop deforestation and manage natural land so that it is healthy, we could achieve up to one third of the emission reductions needed by 2030 to keep global temperatures from rising more than 2°C.
Does vegetarianism have an important positive effect on climate change?
Yes. 60% of mammals on Earth are livestock and 70% of birds are chicken/poultry. Farming livestock uses huge amounts of land (which causes loss of carbon-storing forests) to graze and feed them, and livestock – particularly cattle – emit methane, a very powerful greenhouse gas. Eating less or no meat helps.
How does plastic pollution affect climate change?
Plastic pollution mostly damages marine animals and seabirds who eat it or become trapped in it. Plastic is made with oil and accounts for about 8% of global oil use which is projected to rise over coming years. Recent studies show that, as certain plastics – particularly those that we use to make drinks bottles – sit around, breaking down over time, they start to emit some of the greenhouse gases that cause climate change. Our plastic consumption drives demand for fossil fuel companies to keep ‘exploring’ for and extracting oil.
How do we stop global warming?
The world’s nations need to cut their greenhouse gas emissions substantially and even that would not stop all global warming. The Intergovernmental Panel on Climate Change (IPCC) has calculated that annual greenhouse gas emissions would need to drop at least 40 to 70 percent by mid-century in order to limit global warming to below 2°C. Cutting emissions that sharply is a daunting task. Emissions would then have to keep falling until humans were hardly emitting any extra greenhouse gases by the end of the century. We would also have to remove carbon dioxide from the atmosphere. The IPCC notes that the above task becomes even more difficult the longer we put it off, because carbon dioxide and other greenhouse gases will keep piling up in the atmosphere in the meantime, and the cuts necessary to stay below the 2°C limit become more severe.