Global Warming

The new research lead by the Chinese and American scientists in the Inner Mongolia, partially confirms the unexpected discovery made two years ago: some (wooden) plants produce the greenhouse gas methane, informs the magazine Environmental Science &Technology.

Methane (CH4), the basic component of natural gas is greenhouse gas; its influence on the atmosphere is approximately 25 times stronger than the influence of carbon dioxide. It was recently considered that methane produce, of the living beings, only some types of bacteria under the anaerobic conditions (without the access of oxygen). The basic sources of emissions of methane into the atmosphere are (in descending order) the moistened soils (swamp, flood rice fields), ruminants (bacterium live in their gullets) and some production processes (for example, coking of bituminous coal).

In January, 2006 the group of scientists under direction of Frank Keppler of the Max Planck Institute for Nuclear Physics (Germany), has published in the magazine Nature the article which has inverted idea about the natural production of methane. Investigating the samples of approximately 30 trees and grasses growing in the moderate and tropical forests, Keppler has found out, that they produce (in the presence of oxygen!) certain quantity of methane. Previously it was known that methane produced by soil bacteria can penetrate the stalks of plants, and from there get in the atmosphere, but it was not supposed that the plants produce it.

Discovery had an importance both for biology and for the ecology. First, it has appeared that methane produce not only by bacteria, but also by plants. Secondly, according to the calculations of Keppler, all plants on the planet should throw out in the atmosphere 62-236 million tons of methane per year - it is larger than methane emissions by humidified grounds. This indicated that the estimations of any sources known earlier are strongly overestimated.

In April, 2007 Christopher Butenkhoff and Muhammad Halil have corrected the estimation of Keppler, having shown, that plants throw out 20-60 million tons of methane per year. In July, 2007 Thomas Dueck of Wageningen University (The Netherlands) came out with the suspicion on the validity of Keppler’s result. By means of methods of radiocarbon marking Dueck investigated the whole plants (instead of separate fragments as Keppler) and hasn’t recorded no isolations of methane ,which it would be possible to assign to the vital activity of the plants (i.e., Keppler could fix bacterial methane randomly fallen into the plants). New research of the Chinese- American group under the management of Zhi-Ping Wang of the Chinese Academy of Sciences has impressed both Keppler, and Dueck. Chinese scientists investigated the activities of the fragments of 44 various kinds of plants, growing in the Inner Mongolia. They placed the samples into the hermetic bottles with air, left them in the darkness at a room temperature for 10-20 hours, and then measured change of concentration of methane. The precise methods of radiocarbon labeling, and also the method of processing of samples should exclude an error of which Dueck suspects on Keppler.

The first group (ten grassy plants of moist soils) did not make methane. At two (Glyceria spiculosa and Scirpus yagara) methane was allocated, but not of leaves, but of the stems, therefore it has not been recognized as methane of “vegetative production “. From 25 grassy plants of the second group methane was not produced by any plant. But from nine wood plants of the second group methane was produced by seven wood plants (methane was allocated only from leaves, but not from trunks).

The conclusion is that the plants actually can produce methane, but not all plants, but only some kinds of wood plants. In the ecosystem of the Mongolian steppe it is small quantity of them; therefore the production of methane is insignificant; however, in the ecosystems, where wood plants prevail, can be another circumstances.

On the one hand, both Dueck and Keppler have recognized work of Wang convincing enough. But on another hand, some skeptics assume that Wang could actually fix bacterial methane, by means of complex extending along the plants. Furthermore, it is incomprehensible, why Keppler revealed the production of methane as well in grasses, whereas Wang - only in wood plants. Finally, main problem remains the fact that no one of scientists group thus far can explain how plants produce methane.

Global warming is considered, in many areas of the world, as the sign of an approaching natural cataclysm. Inhabitants of Greenland - autonomous territory in the structure of Denmark, on the contrary, consider that this process has its definite advantages.

As a result of thawing glaciers and stable increase of the temperature which in the summer season already achieves plus 20 degrees on Celsius scale -the vegetative period increases. Thus far on the largest in the world island under difficult conditions of the extreme north basically are limited to plantings of the early ripening varieties of potatoes and cold-resistant turnip. But, as assert experts, because of climate variation soon it will be possible to expand assortment of cultivated vegetables with, for example, cabbage and lettuce. And it is not excluded, considers Greenland farmer Bent Oleson, that in the future the seals hunters and the fishermen will gain knowledge of the cultivation of vegetables and wild strawberries. Oleson himself recently was realigned to the agrarian matter, having constructed in one of the regions of island the network of the greenhouses, which all year long are warmed by means of solar batteries. As a result he succeeded in gathering the pretty good harvest of tomatoes and even bananas with good gustatory qualities.

Scientists have ascertained that the process of melting of the glaciers covering Greenland happens much more rapidly as they assumed before. The area of ice cover in the southeastern part of the island was decreased approximately to 50-100 cubic kilometers per year (till 2004), and now this index grew to 300 cubic kilometers for the analogous period. In other words, according to the data received from the satellites, ices in Greenland thaw four times more rapidly, than a decade ago.