The most frequently asked questions about climate change
Overall, volcanoes release less than 2 percent of the equivalent amount of CO2 released by human activities. Quite small.
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.
However, we can do a lot as societies and individuals to mitigate the effects of climate change and avoid some of the worst-case scenarios – but it will take individual and collective action.
“Weather” refers to the more local changes in the climate we see around us, on short timescales 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.
Do the CCA introductory course on climate change to find out more.
“Weather” refers to the more local changes in the climate we see around us, on short timescales 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.
Do the CCA introductory course on climate change to find out more.
Data from NASA’s GRACE satellites, which measured Earth’s gravity field, show that the land ice sheets in both Antarctica and Greenland have been losing mass (ice) since 2002.
Yes, the vast majority of actively publishing climate scientists – 97 percent – agree that humans are causing global warming and climate change.
While urban areas are warmer than surrounding rural areas, the urban heat island effect has had little to no effect on our warming world, because scientists have accounted for it in their measurements.
“Global warming” refers to the long-term warming of the planet.
“Climate change” encompasses global warming, but refers to the broader range of changes that are happening to our planet, including rising sea levels; shrinking mountain glaciers; accelerating ice melt in Greenland, Antarctica and the Arctic; and shifts in flower/plant blooming times.
Do the CCA introductory course on climate change to find out more.
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.
No. Even if the amount of radiation coming from the Sun were to decrease as it has before, it would not significantly affect the global warming coming from long-lived, human-emitted greenhouse gases. Further, given our greenhouse gas emissions to date and those expected to come, the evidence points to the next “ice age” being averted altogether.
Three of the world’s most complete temperature tracking records – from NASA’s Goddard Institute for Space Studies, the National Oceanic and Atmospheric Administration’s National Climactic Data Center and the UK Meteorological Office’s Hadley Centre – begin in 1880.
Prior to 1880, temperature measurements were made with instruments like thermometers.
The oldest continuous temperature record is the Central England Temperature Data Series, which began in 1659, and the Hadley Centre has some measurements beginning in 1850, but there are too few data before 1880 for scientists to estimate average temperatures for the entire planet.
On average, most of Earth’s mountain glaciers are continuing to melt.
Do the CCA introductory course on climate change to find out more.
Yes, evidence shows warming from 1998 to the present, with the four most recent years (2014, 2015, 2016 and 2017) being the four warmest years globally since 1880.
Do the CCA introductory course on climate change to find out more.
Since satellites technically measure neither temperature nor the surface (where people live), it’s safe to say that ground thermometers are more accurate than satellite measurements.
Ice cores are scientists’ best source for historical climate data.
Other tools for learning about Earth’s ancient atmosphere include growth rings in trees, which keep a rough record of each growing season’s temperature, moisture and cloudiness going back about 2,000 years.
Corals also form growth rings that provide information about temperature and nutrients in the tropical ocean.
Other proxies, such as benthic cores, extend our knowledge of past climate back about a billion years into the past.
The greenhouse effect is the way in which heat is trapped close to the surface of the Earth by “greenhouse gases.”
Do the CCA introductory course on climate change to find out more.
Yes and no. The ozone hole is not causing global warming, but it is affecting atmospheric circulation.
The ozone hole is basically a man-made hole in the ozone layer above the South Pole during the Southern Hemisphere’s spring.
The ozone layer, which lies high up in the atmosphere, shields us from harmful ultraviolet (UV) rays that come from the Sun. Unfortunately we punched a hole in it, through the use of gases like chlorofluorocarbons (CFCs) in spray cans and refrigerants, which break down ozone molecules in the upper atmosphere.
Do the CCA introductory course on climate change to find out more.
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.
Do the CCA introductory course on climate change to find out more.
Source: NASA Global Climate Change
