What do scientists think they know about global warming?

Answer 1

Svante Arrhenius proposed that increasing carbon dioxide could increase earth's temperature back in the late 19th century, well over a hundred years ago. He had no way to prove this, beyond noting that CO2 was a heat trapping (greenhouse) gas.

By the 1950s many scientists began growing concerned about the possibility mankind was unalterably changing his environment, and more precise CO2 monitoring stations were placed in areas around the globe where a careful record of "thoroughly mixed" CO2 could be made. The oldest of these monitoring stations is in Hawaii, and it is sufficiently precise we can detect seasonal variations in CO2 attributable to changing biomass in the northern hemisphere.

We also know humans are currently releasing 40 billion tons of CO2 into the atmosphere each year, and that this gas accumulates. There are no known natural processes removing it as fast as we are emitting it. We have also measured a steady decrease in the ratio of C14 to C12, which indicates the source of the additional atmospheric CO2 is not natural. This decreasing ratio is explained by our consumption of depleted fossil carbon (coal and oil).

Scientists are convinced humans are the primary cause of current global warming, and have been so convinced for well over a decade. Among climate scientists this consensus has grown to exceed 97%.

Scientists predict temperature increases will increase ocean levels, and this prediction has largely been born out. In addition, we can expect many places to experience prolonged periods of drought, while a few areas may receive extra rainfall. Temperate species are expected to increase their range or simply migrate to higher latitudes, while extinction is anticipated for more sessile species. Tropical diseases are expected to achieve wider distribution, and instances of flooding should increase, particularly in lower lying coastal areas.

Answer 2

Scientists belive that Global warming is down to many things, a few of these being: Intensive ranching of cattleDestruction of rainforests Uncontrolled use of fertislizers But mainly down to the greenhouse affect.

Answer 3

Climate scientists agree:

• That burning fossil fuels (coal, oil and natural gas) adds extra carbon dioxide to the atmosphere.
• That trees remove carbon dioxide from the atmosphere through photosynthesis.
• That man's deforestation means there is more carbon dioxide in the atmosphere.
• That carbon dioxide and other greenhouse gases trap heat rising from the surface of the earth.
• That levels of greenhouse gases are rising in the atmosphere and so the atmosphere, the oceans and the land are warming.
• That global warming is happening. It is caused by human activities and it is causing climate change.

Answer 4

Scientists have overwhelming evidence that global warming is real and primarily caused by human activities, such as burning fossil fuels and deforestation. They have observed rising global temperatures, shrinking ice caps, increased extreme weather events, and other impacts that are consistent with climate change predictions. Scientists also agree that urgent action is needed to mitigate the effects of global warming and prevent further irreversible damage to the planet.

Answer 5

Greenhouse gases increase the global warming. It is because they absorb heat and increase the temperature on earth.