The increase of the global average surface temperature of the earth; The increase of the average sea level of the earth; The decrease of the snow cover of the earth.
The climate change may be scientifically evaluated by considering the changes of the following three parameters during long periods of time: The increase of the global average surface temperature of the earth; The increase of the average sea level of the earth; The decrease of the snow cover of the earth.
It can be observed a continuous increase of the global average surface temperature of the earth in the period 1850 2000, a continuous increase of the average sea level of the earth from the year 1870 to 2000 and a continuous decrease of the snow cover of earth's north hemisphere from the year 1921 to 2000.
The increasing and decreasing trend of snow cover area with respect to the change in temperature for all the four months from 2002 to 2012 are shown in Fig. 8a d.
Seven of these are increasing (air temperature in the troposphere; specific humidity; Ocean heat content; rising sea level; sea-surface temperature; temperature over oceans; temperature over land) while three indicators are decreasing (extent of snow cover; volume of glaciers and sea ice).
Furthermore, increasing evidence of decrease in snow cover and retreat of glaciers due to global warming have been reported from various parts of the HKH, which has serious implications for low flow in the region.
As the reflectivity of snow decreases, it's easier to warm the snow and produce melting, says Jan van Angelen, a polar meteorologist at Utrecht University in the Netherlands.
The correlation between atmospheric temperature, total radiation and soil temperature was relatively high, and this effect decreased with the increasing of snow cover.
Precipitation data are scarce in Afghanistan, but regional data show a long-term trend of decreased snow cover, and therefore strong likelihood of decreased aquifer recharge.
Nonetheless, the results in two different modes (event and continuous simulation) provide support to the speculation that the decreasing trend in flood peaks was a result of decreasing snow depth.
