did global warming happened before?

Question

if yes, when it happened? do you think this summer will be hotter than last year? thank you all

Answer 1

it occurs periodically over the millenia. the last warming was probably the result of the ending of the ice age.

Answer 2

Global warming's been happening since forever..

Present warming-
Global warming is the observed increase in the average temperature of the Earth's near surface air and oceans in recent decades and its projected continuation. Models referenced by the Intergovernmental Panel on Climate Change (IPCC) predict that global temperatures are likely to increase by 1.1 to 6.4 °C (2.0 to 11.5 °F) between 1990 and 2100.[1] The uncertainty in this range results from two factors: differing future greenhouse gas emission scenarios, and uncertainties regarding climate sensitivity.

History of warming-
Relative to the period 1860–1900, global temperatures on both land and sea have increased by 0.75 °C (1.4 °F), according to the instrumental temperature record; the urban heat island is not believed to be significant. Since 1979, land temperatures have increased about twice as fast as ocean temperatures (0.25 °C/decade against 0.13 °C/decade) (Smith, 2005). Temperatures in the lower troposphere have increased between 0.12 and 0.22 °C (0.22 and 0.4 °F) per decade since 1979, according to satellite temperature measurements.

more info on global warming-
http://www.epa.gov/climatechange/index.html

global warming FAQ-
http://www.ncdc.noaa.gov/oa/climate/globalwarming.html

Longer growing seasons and warmer winters
More very hot days in summer.

Answer 3

It has, and many times. Each of the ice ages was followed by a period of warming during which the ice melted. The CO2 level during the time of the dinosaurs was four times as high as it is now.