Question

report on global warming kjl,b b

Answer 1

Trends in temperature readings from around the world show that global warming is taking place.

Every one of the past 40 years has been warmer than the 20th century average. 2016 was the hottest year on record. The 12 warmest years on record have all occurred since 1998.

Over the past 130 years, the global average temperature has increased 1.5 degrees Fahrenheit, with more than half of that increasing occurring over only the past 35 years.

Detailed measurements of atmospheric carbon dioxide (CO2) levels have been taken continuously since the late 1950s. The data show that CO2 levels have steadily increased every year. In 2017, they were 28 percent higher than in 1959, the year CO2 measurements began at the Mauna Loa Observatory in Hawaii.

What's more, scientists have detailed records of past CO2 levels from ice core studies, which show that CO2 levels are higher today than at least any point in the last 800,000 years ago.
CO2 absorbs heat reflected from the Earth’s surface — heat that would otherwise pass freely into space. The CO2 then releases that heat, warming the Earth’s atmosphere .

As CO2 levels increase, the pace of warming accelerates. Satellite measurements confirm that less heat is escaping the atmosphere today than 40 years ago. Though other heat-trapping gases also play a role, CO2 is the primary contributor to global warming.

The climate has changed many times in the geologic past due to natural causes — including volcanic activity, changes in the sun’s intensity, fluctuations in Earth's orbit, and other factors — but none of these can account for the current rise in global temperatures.

Scientists can conclusively identify that human activity is responsible for the observed increase in CO2. How? The carbon dioxide emitted by burning coal, natural gas, and oil has a unique chemical “fingerprint" — and the additional CO2 in the atmosphere bears that signature.