Many of us who watched the recent jumbo cabinet meeting at Kalapatthar live on TV must have noticed that the high altitude mountain was barely covered with snow in the background. This brings up a lingering question: Is this proof of “global warming”? But again, since the mountain’s name literally translates to Black Rock in English, obviously it must have been named so way back before the issue of global warming arose. Therefore, the thin snow covering might have nothing to do with “global warming” at all then.
In a series of articles carried by the national media in the past few days (including this paper) the effect of very limited information related to climate science came to the fore akin to the limited and skewed information presented to policy makers. On the basis of such limited information governments around the world are trying to create policies and regulations to deal with global climatic catastrophes. Issues of how Nepal is going to tackle “global warming” or “climate change” especially since the Copenhagen conference is taking place from the Dec 6 to 18, 2009, are being raised on the basis of limited information.
First, it is wholly incorrect to use the terminology “global warming” in a local or regional context because this can give rise to a mistaken notion that temperature everywhere is going to get warmer all around the globe. This is a mistake because while many places on earth may experience temperature rises, other locations may actually cool down. Not all seasons will get warmer neither will days and nights be warm equally or cool for that matter. So, what is really being predicted to happen is “climate change” not ´warming´ in every place on earth.
This leads to the second erroneous belief that is doing the rounds – climate change. It´s as if earth´s climate has never changed in the past. During the 16th century, various locations on the face of the earth underwent a “little ice age” that lasted for decades. River Thames (London) would freeze in the winter during this period; it has not since. Many glaciers expanded their spatial extent during this period. The "little ice age" was actually preceded by what is known as the medieval warming period during the 9th to 14th century AD, when temperatures were higher.
The third point to note is that neither during the "little ice age" nor during the medieval warming period did the global temperature become cold or warm uniformly. In fact, some regions may not have experienced any change altogether. Thus, two things can now be concluded, and policy makers in Nepal can take note: Climate changes, and has always changed, and second, it does not change everywhere at the same time or with the same magnitude.
This then brings me to the fourth point: How has Nepal´s climate changed and how can we predict when and to what extent the change will affect or take place? Will the mountain glaciers expand or retreat? Will the Terai get more or less monsoon rainfall? To answer these questions, the Intergovernmental Panel for Climate Change (IPCC) observes climatic changes and reports them, and to predict the future, it summarizes the results of multiple computer model simulations. According to the fourth IPCC assessment report, the annual rate of increase of the temperature of the Himalayas of Nepal stands at 0.09 degree Celsius and 0.04 degree Celsius in the tarai. The precipitation (rainfall and snowfall) had no distinct trend. Serious and recurring floods have occurred. Projections are that winters are going to get warmer and there will be an increase in annual precipitation with an increase in summer (monsoon) precipitation but decrease in winter precipitation.
My fifth point deals with the robustness of these projections and observations. How reliable are these results? The future projections are from computer model simulations and thus the reliability of these results is wholly dependent on the robustness of the computer models. Do you know how many points (grid cells in climate science terminology) in these computer models is representative of Nepal? Two points. And even these two grid cells do not completely cover the whole of Nepal (it includes parts of India and Tibet). Just imagine, our entire Terai, mountains and valleys are represented by only two points or grid cells! The changes in temperature and precipitation at only these two grid cells in the computer model is the source of the expected temperature and precipitation changes supposed to take place in the future over the whole of Nepal!
Building further on this aspect of the model´s robustness, I request the readers to please note that these computer models are attempting to create our climate from scratch. What do I mean? All that the computer model starts from is the spinning earth, and its distribution of oceans and land, and the solar rays falling on the earth. The model generates the entire global circulation of winds, clouds, precipitation and ocean currents relying on nothing but basic physics: Newton’s Laws of Motion, Conservation of Mass, and Radiation. That the models manage to even simulate the climate is then already a miracle. But, unfortunately, they only get the locations of the deserts, arctic, tropics, etc via temperature and precipitation simulated, the “big picture climate” well. The key to projections, however, is the regional picture. What will happen in Kathmandu Valley, for example, is important; these models cannot predict because, of course, Nepal is only two points in the model. This is my sixth point.
Thus, my seventh point is that global climate models, the source of our understanding of future global climate changes, do not provide any real idea of what is going to happen at specific locations globally and are heavily tuned to simulate the effects of increasing carbon dioxide. But the climate responds too much more than human driven increases of carbon dioxide. It responds to land cover changes, aerosols in the atmosphere and changes in cloud cover, to name a few. These models do not take into account these aspects accurately.
In summary, (to the climate change policy makers and to those who are following the Copenhagen summit): Climate always changes, climate always responds to a variety of drivers, and the climate models can never accurately simulate the climate of Nepal because it is represented by only two points in the models, which can hardly be called accurate and of any real utility. However, to be prepared for any extreme climatic event, similar to those that happened in the past and others that will surely happen in the future, whether humans continue to pump in carbon dioxide into the atmosphere or not, is always a good thing to do. Because climate, of course, always keeps changing.
avantikaregmi@aol.com
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