Studies conducted by James Hansen of the NASA Goddard Institute of Space Research in New York showed that over the past 30 years Earth has been warming by 0,36 degrees Fahrenheit each decade.
Thus, at present the temperature on Earth has reached its highest level in the current interglacial period, which began 12,000 years ago.
The report mentions that, according to research undertaken by the "Nature" magazine, during the past 50 years 1,700 types of plants, animals and insects have been migrating towards the poles at an average speed of 4 miles per decade.
The scientists note that global warming is more noticeable in the region of the Extreme North, where intensive melting of snow and ice have been taking place. This leads to the denudation of land that absorbs the Sun's heat still more.
On the whole, it is rather land surface than oceans that is subjected to warming. Nonetheless, it is manifest in the Indian Ocean and in the western part of the Pacific, giving rise to such phenomena as "El Nino".
All this, says J. Hansen, proves that our civilization has come to a dangerous level of human-caused pollution of environment.
The study conducted by US scientists shows that the rate of the present-day warming that has raised the temperature of Earth by 1 degree Celsius (1.8 degree Fahrenheit) over several decades, may lead to the highest level of temperature over the past several million years.
J. Hansen says that if global warming continues and temperature on Earth goes up by another 2 or 3 degrees Celsius, Earth will become a quite different planet from what we see today. The last time we had it so warm was in the middle of Pliocene, about 3 million years ago, when the sea level was 25 meters higher than today.