September 2005

CSI Fellow, Malin Jennings is beginning to organize her first trip to Greenland to gather indigenous knowledge on climate change. Malin has found a translator and two sled dog guides in Qaanaq, Greenland who are willing to take her to outlying villages. Her next step is to get permission to sleep on the floor of the school or the community center or someone's living room in those villages.

CSI fellow Juerg Brunnschweiler published a paper describing the water escape velocities in free-ranging sharks. Two approximations were used to estimate the swimming speed at the moment of penetrating the water surface. Blacktip sharks were videotaped from below the surface and parameters were estimated by analyzing the sequences frame by frame. Water-escape velocities averaged 6.3 m sK1. The citation is: Brunnschweiler, J.M. 2005. Water-escape velocities in jumping blacktip sharks. J. R. Soc. Interface (2005) 2, 389-391.

Would you like to become a regular contributor to the CSI Report? We are soliciting articles and reports that will interest and inform our readers of your (or your colleagues) work in the field of conservation biology. The article are short and references in the peer-reviewed literature are recommended but the number should be minimized. You can include images or link to images you would like to include in the article, or we can find them for you.

Higher temperatures threaten dangerous consequences: drought, disease, floods, and lost ecosystems. And, from sweltering heat to rising seas, impacts of global warming are being seen in real life and not just movies like “Day After Tomorrow,” the latest being the flooding in western India on July 26, 2005. The floods were caused by the eighth heaviest ever recorded 24-hour rainfall figure of 944 mm (37.16 inches) and were the worst in over a century (The highest 24-hour period in India was 1,168 mm the Union Territory of Lakshadweep in May 2004). The rains killed almost 1000 people and caused damage estimated at 40 billion rupees (US$1.5 billion). It disrupted life in towns of Mumbai, Ratnagiri, Chiplun and Raigad, with many villages swept away in the sudden deluge. The flooding occurred just a week after the heavy rains in the western state of Gujarat and the central state of Madhya Pradesh.

Floods and landslides are common in south Asia during the monsoon season of June to September, when annual rains combine with melting snow from the Himalayas. Villagers at the foothills of the Himalayan Mountains, from Nepal and Bangladesh to India, fall prey to frequent avalanches, floods and landslides unleashed by melting Himalayan glaciers. Similarly, India's western coast receives high rainfall due to the presence Western Ghats or Sahyadri Mountains which lies at about 50 km from the coast. Rain bearing clouds generally deposit much of their moisture in the form of rains along India's western coast. Monsoon flooding in India kills hundreds of people every year across the densely populated country, but this year's rains have been estimated to be one of the worst and most deadly on record.

So what is causing the departure from this natural trend? The scientific reason given for the 2005 flooding was the weakening of the vertical currents. But what is responsible for this weakening? Several other factors are also blamed for the flooding - from silted riverbeds to mismanagement of resources. Geologists blame the reclamation of the natural streams which used to provide natural drainage for the floods. Experts, however, claim that the flooding, which is increasing each year, could be caused by global warming. World Disasters Report 2000, which was published by the International Federation of Red Cross and Red Crescent societies, said: “Reckless human use of fossil fuel, overwhelmingly by industrialized countries, has helped raise the spectra of climate change which darkens everyone's horizon.” And flooding is just one side of the coin, the other being drought. Large parts of western and central India, particularly Gujarat and Rajasthan states bordering Pakistan, were affected by severe drought in 2000 affecting an estimated 50 million people. The number of villages in India experiencing drought is increasing every year. For example, in the state of Gujarat, only 2000 villages experienced drought in 1961, but by 1988, over 145,000 villages were affected. Could global warming be playing a part?

Over the 20th century the average temperature of the earth has increased 0.4-0.8 oC. This increase is expected to continue, and by the 21st century the average global temperature is likely to be 1.4-5.8 oC warmer. Evaporation will increase as the climate warms, which will increase average global precipitation, and it is likely to fall over shorter intervals of time, thereby increasing the frequency of very heavy and extreme precipitation events. In the future, it is expected that many regions will experience more frequent, prolonged, or more severe droughts, primarily due to the more rapid evaporation of moisture from plants, soils, lakes, and other water bodies. This is expected to occur even as precipitation increases and heavy precipitation events become more common. One of the most anticipated effects of climate change is the possible increase in both frequency and intensity of extreme weather events, such as hurricanes, floods, and droughts. The warming of the earth may fuel interactions between the ocean and atmosphere that amplifies the frequency and intensity of extreme weather events. These extreme weather events becoming more frequent. For a country that has more than 70% of its population relying on agriculture directly or indirectly, the impact of extreme weather events is critical. During the last decade India has been repeatedly battered by successive monsoons, flooding and droughts. Cyclones, floods and droughts aren't in themselves new - but how much is global warming likely to worsen them, and how far will countries like India be able to influence the global debate?

Earlier this year a US senator characterized human induced climate change as nothing more than a hoax. The debate still rages in Washington as to whether or not humans indeed are influencing climate. The ratification of the Kyoto Protocol by over 170 countries brought international attention to the issue, but it certainly did not persuade all the disbelievers.

While politicians continue to question climate change, scientists are busy documenting it. In a mere page in the June 3rd issue of Science, a group of researchers have documented one consequence of a shift in global climate. Using satellite images from the early 1970's and the late 1990's they documented the change in arctic lakes in Siberia.

Many studies in the past few years have documented rising temperature in the Arctic. This warming has caused a slight increase in precipitation but this research showed a precipitous decline in the number of lakes in the region. Specifically, the total number of large lakes, those over 40 hectares in size, decreased in size to below 40 hectares. The total amount of surface area covered by lakes decreased by about 6%, and 125 lakes disappeared completely. On the ground studies since the satellite images were taken in 1998 have concluded that none of those lakes have since recovered.

The authors are quick to point out that other studies have shown an increase in the number and extent of lakes in permafrost areas experiencing a warming trend. In particular, they point to thermokarsts as examples, which are slump areas that fill with water. But it appears as though initial warming of the permafrost may lead to expansion of lakes, but over time drainage leads to a decrease in surface area covered by lakes.

This article generated a good deal of attention in the American press. Scientists had predicted that warming would increase lakes and surface area in the arctic with melting permafrost and increased precipitation. But the opposite findings of this study demonstrate how difficult it is to make predictions about what impacts impending climate change will ultimately have.

The Amazon Basin harbors the worlds largest expanse of tropical rainforest and with it an amazing array of biodiversity unparalleled anywhere in the world. But that biodiversity has come under increasing pressure. Deforestation has received widespread attention for over 20 years, but that attention has done little to stem the tide of forest loss.

It may seem surprising, but the Amazon forest remained largely intact until around 1970. Since then about 16% of the Amazon has disappeared. The vast forest once covered an area equivalent to Western Europe, but in the past 35 years an area the size of France has disappeared. In the 1970's and 1980's tax incentives by the government was a principal contributor to deforestation. Although no new incentives have been put in place since 1991, many of the original incentives remain in use.

The government has used monitoring and fines as the primary mechanism to combat deforestation. However, these efforts in many cases have not succeeded. Deforestation has been on the rise since the early 1990's, with soybean plantations posing a major threat in many areas of the Amazon. Opened up after logging roads penetrate deep within the Amazon forest, the combination of roads and conversion of forest to soybean production cause extensive damage to the landscape.

Along with the clearing of trees, logging also dramatically increases the likelihood of forest fire. Even selective logging, once viewed as an acceptable alternative to clearcutting, has negative impacts. Forest gaps opened by selecting large trees increase the amount of sun and wind that reaches the forest floor. This results in dry microclimates that increase the degree of flammability of the forest. Forest fires happen more often as a result and subsequently lead to more damaging fires.

Deforestation not only impacts the forest but also the communities dependant upon them. Loss of tree cover dramatically impacts the water regime. Water recycled in the Amazon has decreased by 20-30% as a result of deforestation. Water vapor that used to linger in the forest now escapes. This leads to drier forests and to a decrease in water available in reservoirs. Deforestation and the changing water regime led to blackouts in Rio de Janeiro and Sao Paulo in 2001. The loss of water vapor can also extend the dry season, which has a dramatic impact on urban centers and the agricultural lands that support them.

Although the most effective means of halting deforestation has been economic recession, the Brazilian government has implemented policies to control forest loss. These primarily include repression through clearing licenses, inspections and subsequent fines. Satellite images showing property boundaries and cutting allocations have helped to discourage illegal land clearing. But making substantial gains will require removing tax subsidies, and other government subsidies, that lead to deforestation.

The author makes a case for a revaluation of the important environmental services the forest provides, notably biodiversity maintenance, carbon storage, and water cycling. While the author demonstrates the potential economic benefit for Brazil through carbon sequestration under the Kyoto Protocol, he has little to say about the economic benefits garnered from biodiversity and water cycling. Without such benefits, continued deforestation in the Amazon remains likely.