Global warming is heating up the earth’s surface over land and water. But some regions are more critically affected than others. One such region is the Himalayan region of central Asia. This region is a huge permanent desert of snow that feeds life-giving rivers of several countries. Several recent studies have shown how global warming is affecting the Himalayas and why much greater efforts are required to stop global warming. 

One of the effects of global warming is that the average temperature of the Himalayan region has increased by 1 degree Celsius since 1970. In some areas the temperature rise is greater. Of greater concern is that the pace of increase is increasing every year. The last 50 years have been the warmest in a thousand years and of the last 50 years the last decade has been the warmest.

In order to accurately record the effects of global warming several climate stations have been established in the Himalayas after 1970. These show that the glaciers in this region are receding at an average rate of 15 meters per year. Some critical glaciers are receding even faster. The Gangotri glacier, which is the source of the River Ganga of India, is receding at 30 meters per year. If this river dries up the fertile plains of northern India will become a barren wasteland. The Khumbu glacier is retreating at almost 100 meters per year. This glacier is a popular route to the summit of Mount Everest, which is in danger of being lost in the years to come. Scientists have estimated that the glaciers of central and eastern Himalayas will dry up by 2035 if global warming continues unabated. 

An event that has been occurring with increasing frequency is the bursting of lakes. The lakes in the higher region of the Himalayas swell with waters from melting glaciers. At some point they break the walls of rock and ice and result in millions of cubic meters of water hurtling down the mountain sweeping away everything in its path. In 1985 the village of Ghat in Nepal was lost this way. Fortunately the watershed happened in the day so there was adequate warning and therefore no loss of life. Bhutan is one of the smaller countries. 24 lakes have been identified that can burst their banks any time. Such are the dangers of global warming.

While flooding is a short-term danger, in the long term there will be severe drought. When the glaciers shrink beyond a level the rivers they feed will dry up. The Indus in Pakistan, the Ganga in India and the Yellow River in China are some of the more important river systems that will be affected by global warming. The population living alongside these rivers will be bereft of drinking and irrigation water.

The irony of the situation is that the Himalayas do not contribute to the global warming, being largely uninhabited. Even the habitation that is there is simple and modest, with the people barely able to eke out a living. But it will be one of the first eco-systems to suffer as a consequence of global warning.

One of the most touted effects of global warming is the rise in sea levels. From 1000 BCE to 1900 CE the average rise in sea level was 0.15 millimeters per year. From 1900 onwards the average rise in sea level was 1.5 millimeters per year. Presently the sea level is rising at 3 millimeters per year. Global warming causes the sea level to rise for two reasons. Higher sea temperatures cause the oceans to expand and the levels to rise. Also higher temperatures cause increased melting of ice, particularly at the poles, and therefore the sea levels to rise. Even the short-term effects of this are worrisome. Cities like London and New Orleans are already requiring storm surge defenses. The Polynesian island of Tuvalu is fast losing land area. In the long-term there would be severe inundation of coastal areas leading to a loss of habitation, agriculture and major changes in land and water quality. This is why it is essential to stop global warming.

Another effect of global warming that is already being felt is increased incidence of extreme weather. Category 4 and category 5 hurricanes have been definitely linked to global warming. El Nino is also a result of global warming. The frequency of El Nino appearing is increasing and it soon may be a permanent phenomenon. El Nino causes widespread climatic changes that lead to natural disasters like flooding, excessive rains, and bush fires.

Some other effects of global warming need to be discussed. Global warming causes a decrease in crop yields. Actual field studies conducted over 12 to 17 years have shown decreased yields in corn, soybean and rice. In fact studies showed that the yield of rice decreased by 10% for 1 degree Celsius increase in temperature. Extinction of species have also been linked to global warming. A study published in Nature in 2004 estimates that 15 to 37% of known species will be extinct by 2050. There are several species, particularly those living in cold habitats, that have a very narrow temperature range. When the temperature rises these species have either to migrate or perish. Evidence shows that some species indeed to migrate whereas others become extinct. Then there are species that have depended on the extinct species for food. These species then too face extinction.

The gravity of global warming can be gauged by the following fact. Even if we are able to control the emissions of gases that cause global warming today, temperatures will continue to rise for a thousand years. Hence we can well imagine the consequences if we are unable to control the emissions of the gases.