The greenhouse effect is the way in which heat is trapped close to the surface of the Earth by “greenhouse gases.”

No. The Sun can influence Earth’s climate, but it isn’t responsible for the warming trend we’ve seen over the past few decades.

“Weather” refers to the more local changes in the climate we see around us, on short time-scales from minutes to hours to days to weeks. Examples are familiar – rain, snow, clouds, winds, thunderstorms, heat waves and floods. “Climate” refers to longer-term averages (they may be regional or global), and can be thought of as the weather averaged over several seasons, years or decades.

Humans have caused major climate changes to happen already, and we have set in motion more changes still. Even if we stopped emitting greenhouse gases today, global warming would continue to happen for at least several more decades, if not centuries.

Yes, but only if we all act now, and act fast. Keeping warming to 1.5° is still possible – but it needs international co-operation to make deep, fast cuts to greenhouse gas emissions. It’s urgent!

Yes, the ocean is continuing to warm. Notably, all ocean basins have been experiencing significant warming since 1998, with more heat being transferred deeper into the ocean since 1990.

Melting land ice, like mountain glaciers and the Greenland and Antarctic ice sheets, will change the Earth’s rotation only if the melt-water flows into the oceans. For example, if the Greenland ice sheet were to completely melt and the melt-water were to completely flow into the oceans, then global sea level would rise by about seven meters (23 feet) and the Earth would rotate more slowly, with the length of the day becoming longer than it is today, by about two milliseconds. Melting sea ice, such as the Arctic ice cap, does not change sea level because the ice displaces its volume and, hence, does not change the Earth’s rotation.

Climate researchers use every possible direct and indirect measurement to study the full history of Earth's climate, from the latest satellite observations to samples of prehistoric ice extracted from glaciers.

Hard to say. But if we do nothing and there’s no improvement then all the climate effects we see now get worse – more extreme weather, with all the harm that does; more pressure on animals and plants that can’t adapt; water scarcity; further loss of sea ice and melting of the ice caps and glaciers. And by then, if we’ve done nothing, then we’ll definitely be on track for 2º and more of warming, with all the really serious impacts we know that carries. A very depressing thought…

Plastic pollution mostly damages marine animals and sea birds who eat it or become trapped in it. But, plastic is made with oil – accounting for about 8% of global oil use, projected to rise over coming years. And recent studies show that, as certain plastics – particularly those that we use to make drinks bottles – sit around, breaking down over time, they do start to emit some of the greenhouse gases that cause climate change. So it is linked, not least because our plastic consumption drives demand for fossil fuel companies to keep ‘exploring’ for and extracting oil.

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. We are already witnessing the devastating impacts of climate change, from life-threatening wildfires and Arctic ice melt, to intense hurricanes and floods. If emissions continue to rise at current rates, we’ve only around a decade before 1.5°C of warming is inevitable and we face climate breakdown.

Click here to see a video of what carbon footprint is. https://www.youtube.com/watch?v=DKDq1RMHscQ

Click here to take the questionnaire to find out your own carbon footprint. https://footprint.wwf.org.uk/#/questionnaire