♠ Posted by Emmanuel in China,Environment
at 6/12/2014 02:00:00 AM
China often gets a bum rap for its environmental performance. This can be unfair as it is with the US continuously harping on the bad air in Beijing when, in reality, the world's most polluted cities in terms of particulates are instead concentrated in the Indian subcontinent. Yes, its overall performance leaves something to be desired, but this is somewhat mitigated by its less-developed status as per the principle of common but differentiated responsibilities and respective capabilities (CBDR/RC). Moreover, there are areas where China is actually doing quite well environmentally-speaking.A case in point is afforestation, or planting trees in areas that did not have them. China's top-down political economy has well-known drawbacks, among them excessive prioritization of growth by officials at the expense of environmental stewardship. On the other hand, efforts to promote afforestation appear to have benefited the environment. Once decided on afforestation from public pressure and fears of deforestation, China began planting trees in droves. Studies suggest benefits are already evident even if locating where to plant trees is an important consideration:
China has the largest afforested area in the world. Afforestation not only contributes to increased carbon storage but also alters local albedo and turbulent energy fluxes, which offers feedback on the local and regional climate. This study presents previously unidentified observational evidence of the effect of large-scale afforestation on land surface temperature (LST) in China. Afforestation decreases daytime LST, because of enhanced evapotranspiration, and increases nighttime LST. This nighttime warming tends to offset daytime cooling in dry regions. These results suggest it is necessary to carefully consider where to plant trees to achieve potential climatic benefits in future afforestation projects.Still, others caution that these afforestation efforts are bound to fail since tree varieties are not often planted in areas suited for them, and the resulting monocultures leave afforested areas vulnerable:
More recently, however, the nation appeared to be reversing that trend, largely with massive campaigns to plant trees. In the first decade of the new millennium, China annually increased its forest cover by 11,500 square miles, an area the size of Massachusetts, according to a 2011 report from the United Nations.Nor are the planting practices of China particularly efficient, they say:
But scientists and conservation groups are beginning to voice concerns about the long-term viability of significant aspects of China’s reforestation push. Of greatest concern is the planting of large swaths of non-native tree species, many of which perish because their water needs are too great for the arid regions in which they are planted. China also is cultivating large monoculture plantations that harbor little biodiversity.
To be sure, trees have been planted, with millions of seeds dropped from airplanes and millions more small seedlings manually planted. But in an extensive analysis of such “afforestation” efforts published last year in Earth Science Reviews, Beijing Forestry University scientist Shixiong Cao and five co-authors say that on-the-ground surveys have shown that, over time, as many as 85 percent of the plantings fail.I think the afforestation effort is admirable even if fine-tuning is involved in a number of respects. First and most obviously, selecting areas which yield climate benefits systematically instead of just seeding vast areas willy-nilly is welcome. Second, tailoring tree varieties to these areas is another good idea. Third, mixing varieties to avoid monoculture is also potentially welcome. Still, it's good to know that even China has some environmental success stories. Go ask the World Bank.