Genesis of Eden Diversity Encyclopedia

Get the Genesis of Eden AV-CD by secure internet order >> CLICK_HERE
Windows / Mac Compatible. Includes live video seminars, enchanting renewal songs and a thousand page illustrated codex.

Join  SAKINA-Weave A transformative network reflowering Earth's living diversity in gender reunion.

Return to Genesis of Eden?

NS 23 feb 2002

Bush's War on Global Climate

THEY stand "shoulder to shoulder" in the war against terrorism. But in the battle to slow global warming, Britain and the US are very much at odds.

Last week Britain published the first draft of a strategy for cutting its carbon emissions by a fifth in the next decade, and by half or more by 2050. Meanwhile, George Bush was announcing a strategy that is likely to boost US emissions by more than a quarter in the coming decade, and who knows what thereafter.

In his first major statement on climate policy since pulling out of the Kyoto Protocol last March, President Bush laid out the new targets for the US: an 18 per cent cut in greenhouse gases for every unit of gross domestic product.

The policy is meant to lower the country's rate of emissions "from an estimated 183 tonnes per million dollars of GDP in 2002 to 151 tonnes in 2012", the White House says. It would "put America on a path towards stabilising greenhouse gas concentrations in the atmosphere in the long run, while sustaining the economic growth needed to finance our investment in a new, cleaner energy structure".

But for Bush the long run is "many generations". The US is already the world's largest emitter of carbon, and even if it meets its target for lowering emissions per unit of GDP, its overall emissions are likely to rise rapidly as the economy grows. "This will leave the US producing at least 35 per cent more greenhouse gases in 2010 than would be permitted under the Kyoto Protocol," says Chris Flavin, president of the Worldwatch Institute in Washington DC.

Britain's strategy comes from an energy review by the Prime Minister's think tank, the Performance and Innovation Unit, and is not yet government policy. It proposes a 20 per cent improvement in energy efficiency by 2010, and says renewable energy such as wind and solar power should provide a fifth of the country's electricity by 2020. It leaves open the options of building more nuclear power plants and of cleaning up future coal-burning power stations by capturing CO~ as it is produced.

Bush did announce tax breaks for wind and solar energy, for running cars on fuel cells and for farmers and foresters who find ways to lock up more carbon on their land. But he reckons that meeting the 7 per cent cut that the Clinton administration had promised under the Kyoto Protocol would have cost $400 billion and put nearly 5 million Americans out of work.

The British report, by contrast, concluded that the costs to the economy of even big cuts in emissions are likely to be small. And it takes the threat posed by climate change far more seriously. It declares that there is "a strong likelihood that the UK will need to make very large carbon emission reductions over the next century".

Bush's plan has outraged many around the world, who see it as a dismal-if not unexpected-failure to deliver the credible alternative to Kyoto he promised. But Bush claims his approach of reducing emissions per unit of GDP could attract the support of developing nations. "The greenhouse gas intensity developing countries a yardstick for progress on climate change that recognises their right to economic development," he says. Fred Pearce

Something to smile about Genetically modified bacteria could save your teeth

TOSS away that toothbrush. A single trip to the dentist as a toddler could be all you need to keep tooth decay away for life. But there's a catch. You have to be willing to open your mouth to an invasion of genetically modified bacteria.

The scheme involves replacing your mouth's natural cavity-causing bacteria with GM bacteria designed to prevent tooth decay. "My goal was to construct a good version of bad bacteria, " says dental researcher Jeffrey Hillman at the University of Florida in Gainesville.

The GM bacteria would replace a bug called Streptococcus mutans, which colonises most people's mouths and causes about 85 per cent of all dental cavities. It does this by converting sugar to lactic acid that slowly etches away tooth enamel.

To make his GM bacteria, Hillman set out to find a bacterium that was incapable of secreting lactic acid and that could kill and completely replace the harmful S. mutans. After collecting samples from the mouths of hundreds of patients in the early 1980s, he hit upon a strain that can wipe out S. mutans by secreting a bacterial toxin. The toxin is deadly to other types of bacteria too, but Hillman's variant didn't kill other, helpful bacteria in the mouth or in the gut because the toxin doesn't travel far from where it is produced.

But the bacterium wasn't perfect-it still secreted lactic acid and so could cause cavities. To disarm it, Hillman and his colleagues removed the gene that codes for lactate dehydrogenase, the enzyme that converts sugars to lactic acid. They called the new strain BCS3-L1.

BCS3-L1 can be brushed or squirted onto the teeth in a formulation that Hillman says tastes like chicken soup. When applied to the teeth of rats, BCS3-L1 dramatically reduced cavities.

Hillman and his company OraGen of Alachua, Florida have not yet had permission from the Food and Drug Administration to test the therapy in humans. But three human subjects who volunteered to have BCS3-Ll's parent strain applied to their teeth in the early 1980s still have no S. mutans in their mouths. The volunteers have not passed the GM bacteria to their partners or children, indicating that it cannot be spread by kissing.

Other researchers are working on a vaccine against cavity-causing bacteria (New Scienfist, 15 September 2001, p 17). But Hillman says it is much easier to tinker with bacteria than with the human immune system.

Ideally BCS3-L1 should be swabbed onto children's teeth at about the age of two, before toddlers have had chance to acquire the S. mutans bug by sharing such things as drinks with others. Hillman estimates the treatment could cost about $100 per child and take five minutes. Catherine Zandonella

All fished out

Get ready for a new kind of cucumber sandwich

NORTH Atlantic cod may never recover from the effects of overfishing, forcing us to eat less palatable species such as sea cucumber and jellytish.

Stocks of cod crashed 10 years ago, and a fishing ban wa~put in place off the east coast of Canada to allow them to recover. But it ~ay be too late, says Alida Bundy from the Bedford Institute of Oceanography in Nova Scotia: the population dynamics of cod have been altered so severely that they might never reappear in their former numbers. Adult cod prey on species such as herring and mackerel that compete with or eat juvenile cod, she says. It's possible that without a big population of adult cod, the juveniles never get a chance to grow.

Her warning comes alongside a new model suggesting that overall fish numbers are continuing to decline in the North Atlantic. According to the first comprehensive model of the entire North Atlantic, the number of catch species has drastically declined over the past century, and continues to fall by about 2 per cent each year because of overbshing.

The model, developed by an international team of scientists and led by Daniel Pauly of the University of British Columbia, suggests that the amount of high-quality table fish such as cod, tuna, haddock and flounder has fallen to about 13 million tonnes-a sixth of what it was in 1900.

aThe North Atlantic will continue to be overbshed as long as you're trying to find someplace for all those fishing boats to go, " says Andrew Rosenberg, a member of the team from the University of New Hampshire. "Less is actually more with fisheries. If you fish less you get more fish."

The model also shows that catches have fallen by about half since 1950, despite a tripling of the effort that goes into fishing. ! Government subsidies to North Atlantic fisheries totalling about $2.5 billion a year are intended to cut down on overfishing by giving fishermen another source of income. But the team says this has only driven fishermen to catch other species rather than stopping fishing altogether.

"JellyLish is already being exported, " says Pauly. "In the Gulf of Maine people were catching cod a few decades ago. Now they're catching sea cucumber. By the standards of a few decades ago these things were repulsive," he says. If things don't change, says Reg Watson from the University of British Columbia, "we'll all be eating jellyfish sandwiches". Kurt Kleiner

Muddy waters

Corals are being robbed of light

IT'S not just warmer water that's making life difficult for coral reefs. The oceans are getting murkier, and that's stunting reef growth.

Sunlight is essential for coMI reefs. Symbiotic algae called zooxanthellae living in the corals photosynthesise to produce carbohydrates and oxygen that the corals use to make reef-building calcium carbonate. If waters become less transparent this process is harmed, says Charles Yentsch of the Bigelow Laboratory for Ocean Sciences in West Boothbay Harbor, Maine.

He and his colleagues found that some reefs in the Florida Keys are getting barely enqu`,gh sunlight to sustain themselves. The reefs are functioning close to the "compensation point"-where the coral and the zooxanthellae use up all the products of photosynthesis just to survive, leaving little or nothing to build onto the reef. Yentsch says that coral reefs in the Bahamas are similarly endangered. As the water gets murkier the corals are also forced to move towards shallower water, where waves can damage them. "They are kind of caught between the jaws of a vice," says Yentsch.

The development of coastal areas and the erosion of beaches are partly to blame for the increasingly murky waters. Loss of coastal mangroves and seagrass beds from lagoon floors and reef flats adds to the problem, as they would normally trap sediment before it reaches the coral reefs. In addition, an increase of fertiliser run-off into the ocean, from sugar-cane farms in Jamaica, for instance, is encouraging algal blooms.

"The transparency has changed significantly in the past 10 or 20 years, so that the amount of light reaching the reef corals in some areas is really too low to sustain dynamic growth," says Yentsch. "I think it's had a major effect."

However, the two biggest causes of coral death are still overfishing and climate change, says Gregor Hodgson, director of the Reef Check Foundation in Los Angeles. "It is safe to say that a significant proportion of the world's reefs are not located in coastal areas affected by sedimentation," he says. But he accepts that the murky waters might be a problem for a few coral reefs in specific spots around the globe. Anil Ananthaswamy More at: Journol of Experimental Marine 8iology and

Ecology Ivol 268, p 171}

Bigger ain't better

Brain size alone doesn't explain why we're intelligent

WHY are people brighter than chimps? Many think it's because the part of the brain linked to intelligence, the frontal cortex, is much bigger in people than in apes when compared to overall brain size. But now it turns out this isn't true at all: that part of our brains is actually about the same relative size.

Two key reports published in 1912 and 1968 suggested that people have larger frontal cortices relative to their overall brain size than monkeys or other mammals. Because the frontal cortex turned out to be a key centre for problem-solving, planning and general intelligence, researchers suggested that it might explain why humans have such unique brainpower.

But these reports were based on limited studies. They looked at only one or two brains from a few species, and didn't include most of the great apes. What's more, the animals were dead, and it's possible that some brain regions had shrunk more than others after death. Other small studies since then have come up with conflicting results.

Now Katerina Semendeferi from the University of California at San Diego has looked at the brains of a far larger sample of living animals using magnetic resonance imaging. Her team analysed brain scans of 15 great apes-chimps, bonobos, gorillas and orang-utans-along with four gibbons and five monkeys, and compared the results to brain scans from 10 people.

Monkeys and gibbons did indeed have a relatively small frontal cortex as a percentage of their overall cerebral cortex size-gibbons, for example, averaged 29 per cent. But the relallvely small rromal corlex as a percentage figure for people and all the great apes was at least 35 per cent. Both humans and orangutans, for example, averaged 38 per cent.

Richard Passingham, an Oxford University neuroscientist, points out that there's another way of explaining why humans are brighter than chimps. It could be that the size of the entire brain in comparison to body size is the crucial point. This ratio is roughly constant for most animals. Elephants, for instance, have huge brains because they have to control so much muscle.

But people have far larger brains for our body size than other primates, so our frontal cortices are larger too. nThey must be over three times larger than would be expected for a hypothetical great ape of the same weight," says Passingham. "Such a difference must be of immense consequence for our capacity to plan and reason."

Semendeferi says that the difference in brainpower between people and chimps may not depend on size alone. Instead, it could be down to better neural circuits connecting parts of the frontal cortex. "Behaviours are supported by neural systems, not localised chunks of tissue," she says.

Or it may be due to the relative size of more specialised parts within the cortex itself. Both Passingham and Semendeferi agree that researchers need to look more closely at the sizes of these smaller regions. It may be that a section like the prefrontal cortex- central to high-level human thinking, creativity and emotion-is larger in people than in apes by any measure. Hazel Muir

More at: Nature Neuroscience {DOI 10.1038/nnB14}

In hot water

THE sea around Antarctica is warming twke as fast as the rest of the world's - raising fears of a catastrophe in the region.

The Southern Ocean is warming - the conserquences are likely to be significant says Mike Meredith, an oceanographer at the British Antarctic Survey in Cambridge.

Traditionally, the Antarctic's Southem Ocean has always been difficult to study because of its isolation and severe weather. lt's a miserable place to go to sea," says Sarah Gille, from the Scripps Institution of Oceanography in San Diego, who has come up with the first clear picture of temperature changes there.

Since 1990, researchers have released large numbers of robotic buoys which send back data via satallite. To work out how the temperature has changed, Gille had to combine this data with measurements taken from ships since the 1930s.

The results are a shock. The temperature 700 to 1100 metres down rose by 0.17 °C between the 1950s and 8U0s, almost twice as much as the global oceans as a whole. That doesn't sound like much but keep in mind that at these depths we nommally think the ocean is isotated from changes on the surface," she says. Just how the deeper water could heat up so quickly is a mystery.

If the warm water melts sea ice, that woutld adversely affect the aIgae that usually grow on its underside. Algae are an important food source for krill which, in tum, are food for tlarger fish and mammals. "The entire ecosystem coutd be damaged," says Meredith.

Another worry is that any warming could reduce the Southern Ocean's storage capacity for huge volurnes of dissolved carbon dioxide. That could tead to an increase in carbon dioxide in the atmosphere and greater global warming.

Meredith says we'lt need to work hard to understand the wamming and its effects. "R's very difficult to know exactly what witl happen but it certainty deserves further investigation." Justin Mutlins More at: Scknce {wt 295, p 1215}

Green harvest

Chemical-free farming is paying dividends for the world's poor

ORGANIC farming, once seen as a fad for overfed Westerners, is increasingly feeding the poor world too.

"Farmers in developing countries are reaping the benefits of green agricultural practices far more than their Western counterparts," says a study launched last week at a conference in Nuremburg on organic farming. "In the West, the myth is that organic farming means lower yields," adds the study's author, Nicolas Parrott of Cardiff University. "But in the developing world that does not apply, especially among poor farmers who can't afford massive amounts of fertiliser and pesticides. For them, it raises yields."

Often, farmers turn to organic methods only reluctantly, as governments withdraw subsidies for agrochemicals or as pests become resistant to pesticides. But they are sometimes surprised by the results. - For instance, cotton farmers in the Indian state of Madhya Pradesh all but gave up production after the main pest there, the whitefly, became resistant to common pesticides. To rescue the business, one cotton mill - encouraged its suppliers to grow weeds that lure the flies away. Seven years on, yields are up 20 per cent, labour and production costs have fallen by 30 per cent, and more than 1000 farmers cultivating more than 6000 hectares have joined the scheme. Cuba had to shift to organic farming methods after the collapse of the Soviet Union cut its supplies of expensive agro-chemicals. Local scientists recruited a parasitic fly to keep cane borers out of suga fields, a predatory ant to tackle weevils on sweet potatoes, and a wasp to stop caterpillars eating their way through cassava fields. Today, 65 per cent of Cuba's rice and 50 per; cent of its fresh vegetables are produced organically, Parrott says.

ln other examples highlighted in the report, which was co-sponsored by Greenpeace, rice farmers in Madagascar have upped yields from 3 to 10 tonnes per hectare. And Brazilians doubled their maize yields by using crop residues and alternating maize with other crops to improve the fertility of their soils.

The findings mirror a similar study by Jules Pretty of the University of Essex last year. He found average yield increases of 73 per cent on projects in the developing world that used sustainable methods, often organic. In all, the projects covered 3 per cent of Third World fields (New Scientist,

3 February 2001, p 16). Fred Pearce