After the Japan disaster, the question has come back to haunt us - whether the planned addition of more than 60,000 MW of nuclear power by 2031-32 (as per
Integrated Energy Policy) is in the interest of our society? What are risks associated with nuclear parks like Jaitapur, and other ones in West Bengal, Gujarat, in a nation as populated as India? This is besides the huge cost involved in nuclear power production. Not to forget the problem of waste - Tarapur has 40 years of nuclear waste accumulated and not knowing what to do with it!
Proponents say the explosion at Japan's reactors is not relevant to India where we have safer concrete domes. Well, Kaiga dome did collapse! Also, they say that In India nuclear plants are not placed close to inhabitation.?? If it is about self-sufficiency and 'clean' (can nuclear waste ever be clean?), then nuclear is the best choice, some say.
India's nuclear programme is of 3 stages. At present we are using natural uranium. From it we get plutonium which will be used in 2nd stage reactor. From outcome of 2nd stage reactor we will be getting thorium which will be used in third generation reactor. India has a vast source of thorium which is expected to last for minimum of 460 year. The plan and design is ready for third generation reactor.And then, the nation will be self sufficient. That is the claim.
Is nuclear the only clean option? Or does the solution lie in deploying small, distributed energy sources using those available locally? Or is it in aggressively adopting renewables?
Monday, March 14, 2011
Save 'blue carbon'
Dubbed "blue carbon" because of their littoral environment, mangroves, salt marshes and sea grasses previously undervalued, these coastal carbon sinks are beginning to gain attention from the climate and conservation communities. They can sequester vast amounts of carbon—up to five times that stored in tropical forests.
Because they hold so much carbon, destroying them can release substantial amounts of CO2. People around the world wreck coastal habitats through aquaculture, agriculture, timber extraction and real estate development. To date, human encroachment has destroyed more than 35 percent of mangroves, 30 percent of sea grass meadows and 20 percent of salt marshes.
Stopping such destruction could therefore become an important element in confronting climate change. At the global scale, coastal wetland destruction could account for 1 to 3 percent of industrial emissions; a number that will increase along with coastal wetland destruction.
According to scientists, the main hope for conserving these coastal habitats lies in a combination of economics and science. The first step is recognizing the importance of coastal carbon pools as a significant tool for climate mitigation.
Even without carbon markets nations have obligations to manage their greenhouse gas emissions, which means that the carbon in these coastal habitats can be tallied in national accounts as a way of contributing to their management of global greenhouse emissions. Companies, say the experts, could also start volunteering to launch socially and environmentally friendly coastal habitat projects in the name of climate protection.
Because they hold so much carbon, destroying them can release substantial amounts of CO2. People around the world wreck coastal habitats through aquaculture, agriculture, timber extraction and real estate development. To date, human encroachment has destroyed more than 35 percent of mangroves, 30 percent of sea grass meadows and 20 percent of salt marshes.
Stopping such destruction could therefore become an important element in confronting climate change. At the global scale, coastal wetland destruction could account for 1 to 3 percent of industrial emissions; a number that will increase along with coastal wetland destruction.
According to scientists, the main hope for conserving these coastal habitats lies in a combination of economics and science. The first step is recognizing the importance of coastal carbon pools as a significant tool for climate mitigation.
Even without carbon markets nations have obligations to manage their greenhouse gas emissions, which means that the carbon in these coastal habitats can be tallied in national accounts as a way of contributing to their management of global greenhouse emissions. Companies, say the experts, could also start volunteering to launch socially and environmentally friendly coastal habitat projects in the name of climate protection.
Tuesday, March 8, 2011
Mass extinction predicted
Scientists from the University of California, Berkeley warn that we are on the brink of pushing the planet into its sixth mass extinction if something isn’t done soon. With the steep decline in populations of many animal species, from frogs and fish to tigers, some scientists have warned that Earth is on the brink of a mass extinction like those that occurred only five times before during the past 540 million years.
However, it isn’t too late to save these critically endangered mammals and other species, and bring us up short of a tipping point which would lead to the planet’s sixth mass extinction. It is very important to devote resources and legislation toward species conservation if we don’t want to be the species whose activity caused a mass extinction, note the team.
After looking at the list of threatened species maintained by the International Union for Conservation of Nature (IUCN), the team concluded that if all mammals now listed as “critically endangered,” “endangered” and “threatened” go extinct, whether that takes several hundred years or 1,000 years, Earth will be in a true mass extinction. The findings highlight how essential it is to save critically endangered, endangered and vulnerable species, to ensure the Earth’s biodiversity remains in pretty good shape.
However, it isn’t too late to save these critically endangered mammals and other species, and bring us up short of a tipping point which would lead to the planet’s sixth mass extinction. It is very important to devote resources and legislation toward species conservation if we don’t want to be the species whose activity caused a mass extinction, note the team.
After looking at the list of threatened species maintained by the International Union for Conservation of Nature (IUCN), the team concluded that if all mammals now listed as “critically endangered,” “endangered” and “threatened” go extinct, whether that takes several hundred years or 1,000 years, Earth will be in a true mass extinction. The findings highlight how essential it is to save critically endangered, endangered and vulnerable species, to ensure the Earth’s biodiversity remains in pretty good shape.
More carbon, less water
Doubling today's carbon dioxide levels will dramatically reduce the amount of water released by plants and hence the rainfall. A doubling of today's carbon dioxide levels -- from 390 parts per million to 800 ppm -- will halve the amount of water lost to the air, leading to altering the hydrological cycle and climate.
As carbon dioxide levels have risen during the last 150 years, the density of pores that allow plants to breathe has dwindled by 34 percent, restricting the amount of water vapor the plants release to the atmosphere, report scientists from Indiana University Bloomington and Utrecht University in the Netherlands in an upcoming issue of the Proceedings of the National Academy of Sciences.
Most plants use a pore-like structure called stomata (singular: stoma) on the undersides of leaves to absorb carbon dioxide from the air. The carbon dioxide is used to build sugars, which can be used by the plant as energy or for incorporation into the plants' fibrous cell walls. Stomata also allow plants to "transpire" water, or release water to the atmosphere. Transpiration helps drive the absorption of water at the roots, and also cools the plants in the same way sweating cools mammals.
If there are fewer stomata, or the stomata are closed more of the day, gas exchange will be limited -- transpiration included.
If transpiration decreases, there may be more moisture in the ground at first, but if there's less rainfall that may mean there's less moisture in ground eventually. This is part of the hyrdrogeologic cycle. Land plants are a crucially important part of it. While it is well known that long-lived plants can adjust their number of stomata each season depending on growing conditions, little is known about the long-term structural changes in stomata number or size over periods of decades or centuries.
Yet another vicious circle!
As carbon dioxide levels have risen during the last 150 years, the density of pores that allow plants to breathe has dwindled by 34 percent, restricting the amount of water vapor the plants release to the atmosphere, report scientists from Indiana University Bloomington and Utrecht University in the Netherlands in an upcoming issue of the Proceedings of the National Academy of Sciences.
Most plants use a pore-like structure called stomata (singular: stoma) on the undersides of leaves to absorb carbon dioxide from the air. The carbon dioxide is used to build sugars, which can be used by the plant as energy or for incorporation into the plants' fibrous cell walls. Stomata also allow plants to "transpire" water, or release water to the atmosphere. Transpiration helps drive the absorption of water at the roots, and also cools the plants in the same way sweating cools mammals.
If there are fewer stomata, or the stomata are closed more of the day, gas exchange will be limited -- transpiration included.
If transpiration decreases, there may be more moisture in the ground at first, but if there's less rainfall that may mean there's less moisture in ground eventually. This is part of the hyrdrogeologic cycle. Land plants are a crucially important part of it. While it is well known that long-lived plants can adjust their number of stomata each season depending on growing conditions, little is known about the long-term structural changes in stomata number or size over periods of decades or centuries.
Yet another vicious circle!
Monday, March 7, 2011
Damn the dams?
Floodwaters from the Xiol
Are dams good, or is coal better or is nuclear the best option? You are sure to hear proponents of each espousing the respective energy option. What is the truth? Does it as always lie somewhere in between?
To reduce its carbon intensity by 40 percent by 2020, China has undertaken a five year plan with grandiose plans, among which are big dams. As part of its low-carbon diet, the Chinese government plans to approve new hydropower plants with a capacity of 140 gigawatts over the next five years. For comparison, Brazil, the United States and Canada have each built between 75 and 85 gigawatts of hydropower capacity in their entire history. Achieving the new plan's target would require building cascades of dams on several rivers in China's south-west and on the Tibetan plateau.
Experts believe this would spell disaster for its rivers and biodiversity hotspots. Because of dam building and other factors, freshwater species have on average lost half their populations between 1970 and 2000, and more than a third of all freshwater fishes are at risk of extinction.
International pressure to limit greenhouse gas emissions is the single most important factor behind the huge push for hydropower in China. But, in the process is it set to create new crises? Should emissions reductions come at the cost of biodiversity and loss of rivers?
Friday, March 4, 2011
Natural gas: the next choice to coal?
Well, if solar and wind come with their set of problems, is natural gas a better option? Should we opt for more pipes rather than wires overhead?
Natural gas advocates argue that it generates 50 percent fewer greenhouse gases than coal when burned. And since natural gas is more widely available than ever, thanks to newer more efficient—though in some cases environmentally damaging—extraction techniques, some think it should be playing a larger role in a transition away from coal.
But although natural gas generates less greenhouse gas than coal when burned, when its total life-cycle emissions associated with extraction and distribution are factored in, it does not seem much cleaner than coal. A 2007 lifecycle analysis of natural gas production, distribution and consumption found that when one factors in the total emissions associated with not only the end use of natural gas but also its extraction and distribution—much of it can leak when it is pulled out of the ground and then piped to power plants and other customers—it doesn’t seem so much cleaner than coal after all. The U.S. Environmental Protection Agency (EPA) says that loose pipe fittings and intentional venting for safety purposes on natural gas lines cause annual greenhouse gas emissions rivaling that produced by 35 million cars each year.
The World Bank estimates that emissions from natural gas extraction operations alone account for over a fifth of the atmosphere’s total load of climate-changing methane.
“When scientists evaluate the greenhouse gas emissions of energy sources over their full lifecycle and incorporate the methane emitted during production, the advantage of natural gas holds true only when it is burned in more modern and efficient plants,” reports Abrahm Lustgarten on the investigative news website, ProPublica. “But roughly half of the 1,600 gas-fired power plants in the United States operate at the lowest end of the efficiency spectrum.”
Definitely, solar and wind seem more benign!
Natural gas advocates argue that it generates 50 percent fewer greenhouse gases than coal when burned. And since natural gas is more widely available than ever, thanks to newer more efficient—though in some cases environmentally damaging—extraction techniques, some think it should be playing a larger role in a transition away from coal.
But although natural gas generates less greenhouse gas than coal when burned, when its total life-cycle emissions associated with extraction and distribution are factored in, it does not seem much cleaner than coal. A 2007 lifecycle analysis of natural gas production, distribution and consumption found that when one factors in the total emissions associated with not only the end use of natural gas but also its extraction and distribution—much of it can leak when it is pulled out of the ground and then piped to power plants and other customers—it doesn’t seem so much cleaner than coal after all. The U.S. Environmental Protection Agency (EPA) says that loose pipe fittings and intentional venting for safety purposes on natural gas lines cause annual greenhouse gas emissions rivaling that produced by 35 million cars each year.
The World Bank estimates that emissions from natural gas extraction operations alone account for over a fifth of the atmosphere’s total load of climate-changing methane.
“When scientists evaluate the greenhouse gas emissions of energy sources over their full lifecycle and incorporate the methane emitted during production, the advantage of natural gas holds true only when it is burned in more modern and efficient plants,” reports Abrahm Lustgarten on the investigative news website, ProPublica. “But roughly half of the 1,600 gas-fired power plants in the United States operate at the lowest end of the efficiency spectrum.”
Definitely, solar and wind seem more benign!
Thursday, March 3, 2011
Now, who will stop the wind?
The spectacular growth in recent years in the number and size of renewable energy sources across the European Union -- particularly wind and solar power -- driven by high subsidies and government rhetoric on climate change has left the national electricity grids scrambling to cope. Estimated costs of strengthening, upgrading and smartening the grids are put at up to €100 billion ($138 billion) over the next decade alone. And that only takes into account onshore networks.
A study earlier this year by German company Energynautics commissioned by Greenpeace found that grid upgrades totaling up to 140 GW of capacity would be necessary across the European Union and eastern and northern Europe to cope with the vast increase planned in renewable energy.
Germany produces only about 5 gigawatts of actual wind power, and when recently that output shot up to a record of more than 20 GW on a particularly windy weekend, cross-border connections to grids in neighboring countries had to be shut down because they couldn't handle the surging power. The Germans need to build 17,000 kilometers of new grid just internally.
With the United Kingdom, for one, aiming to get some 30 GW of electricity from wind farms in the North Sea within the next decade as part of its E.U. target to get 15 percent of its power from renewables by 2020, there are also proposals to build a giant subsea grid to bring that power ashore.
Problems are not just of power loss and heat generation over long distances, but also of public acceptability and cost. As with onshore wind farms, there is frequent public outcry over the placement of power pylons while placing it underground has technical issues like cooling.
Countries are still struggling to build their own networks, let alone when it comes to crossing borders and the only country really doing it is China, using European technology!
So do we see a problem of plenty, or that of being unprepared? And do we learn a lesson from the early beginners?!
A study earlier this year by German company Energynautics commissioned by Greenpeace found that grid upgrades totaling up to 140 GW of capacity would be necessary across the European Union and eastern and northern Europe to cope with the vast increase planned in renewable energy.
Germany produces only about 5 gigawatts of actual wind power, and when recently that output shot up to a record of more than 20 GW on a particularly windy weekend, cross-border connections to grids in neighboring countries had to be shut down because they couldn't handle the surging power. The Germans need to build 17,000 kilometers of new grid just internally.
With the United Kingdom, for one, aiming to get some 30 GW of electricity from wind farms in the North Sea within the next decade as part of its E.U. target to get 15 percent of its power from renewables by 2020, there are also proposals to build a giant subsea grid to bring that power ashore.
Problems are not just of power loss and heat generation over long distances, but also of public acceptability and cost. As with onshore wind farms, there is frequent public outcry over the placement of power pylons while placing it underground has technical issues like cooling.
Countries are still struggling to build their own networks, let alone when it comes to crossing borders and the only country really doing it is China, using European technology!
So do we see a problem of plenty, or that of being unprepared? And do we learn a lesson from the early beginners?!
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