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Climate Warming, Grapes and Methane

Climate warming and its affect on grape growing; and has the World’s production of methane slowed?
by Art Drysdale
by Art Drysdale


Art Drysdale, a life-long resident of Toronto and a horticulturist well known all across Canada, is now a resident of Parksville, British Columbia on Vancouver Island, just north of Nanaimo. He has reno-vated an old home and has a new garden there. His radio gardening vignettes are heard in south-western Ontario over radio station Easy 101 FM out of Tillsonburg at 2 PM weekdays.

Art also has his own website at

December 7, 2003

In the past few months, I visited the famous Cathedral Grove Provincial Park here twice, and right now it is very much in the news in British Columbia. The province wants to build a new parking lot for the park, on a flat area near the park. Environmentalists oppose any encroachment on the land. However, the dangers of the present parking arrangements are very severe, a new arrangement is needed. These photos show the largest tree in the park (7 young kids wide!) and a brief story of the size of the trees we have here. Author photos.

According to a report by Betsy Mason in Nature magazine in November (4th), “Rising temperatures are giving some of the world's top wine regions a boost and fuelling new vineyards. But warming could also threaten the distinctive flavour of some harvests, says climatologist Gregory Jones of Southern Oregon University in Ashland. ‘In most regions over the past decade, every year has been great for wines,’ Jones told the annual meeting of the Geological Society of America in Seattle, Washington. ‘Undoubtedly, climate played a significant role in this trend.’

Gregory “Jones studied 30 types of wine from 27 different regions, including parts of France, Italy, Portugal, Germany, California, Chile and South Africa. He found close links between vintage ratings--a zero to 100 scale--for each wine and climate records from the past 50 years. The temperature rose by an average of 2 ºC during this time, and wines experienced an average rating increase of 13.3 for each degree. This is enough to bump a 'good' wine into the élite category of bottles ranked higher than 90.

“To look to the future, professor Jones used a global climate model developed at the Hadley Centre for Climate Prediction and Research in Bracknell, UK. It forecasts a gain of a further 2 ºC for most wine-growing regions over the next 50 years. As temperatures climb, vintages become more consistent, says Jones. This could be good news for areas such as Germany's Rhine valley, which has big swings in quality from year to year.

“Warmer temperatures are already allowing vineyards to spring up in northern areas where grapes couldn't survive just a few decades ago. England's fledgling wine industry, for example, could improve in the coming years if the current climate trend persists, he says. ‘It may not be the best wine region in the world in 50 years, but it could get better.’ But, warming spells trouble for hotter areas that are already producing consistently good vintages, including Italy's Chianti region and the northern Rhone valley in France.

“Average temperature in the Rhone valley has gone up by around 4 ºC over the past 50 years. If this trend persists, harvests could come earlier, exposing picked grapes to warmer temperatures. Grapes that ripen too quickly have the right amount of sugar, but may produce a wine that is short on flavour. Gregory Jones is confident that the industry can handle the shifts. ‘Grape-growers can deal with the change in climate, but they need to be aware of them,’ he says.”

Another report, this one by Helen Pearson, in an even more recent issue of Nature magazine (28th) deals with the highly controversial topic of global warming and the release of Methane gas into the air world-wide. According to the author, “Levels of the greenhouse gas methane have plateaued for the first time in around 200 years. Methane is second only to carbon dioxide in contributing to our planet's warming. The gas--belched out by fossil-fuel burning, rice paddies, festering farm manure and landfill sites--has been accumulating steadily since the Industrial Revolution.

“Now the tide may be turning, say Ed Dlugokencky of the National Oceanic and Atmospheric Administration (NOAA) in Boulder, Colorado, and his team. They found that levels steadied between 1999 and 2002, according to measurements from 43 ground-based stations around the world. The reason for the change is unclear. Ed Dlugokencky believes that a major contributing factor was the break-up of the Soviet Union in 1991. Oil and gas production fell, and the industry became more efficient at plugging gas leaks from pipes and wells.

“Experts are keen to point out that the plateau is no cause for complacency. Increasing fossil-fuel consumption in developing nations, or renewed drilling for natural gas, might boost methane again. ‘The trajectory is still moving up, in my opinion,’ says atmospheric chemist David Blake of the University of California, Irvine. Indeed, says Blake, the finding highlights how small steps to cut methane emissions could slow global warming. Leaking gas pipelines could be capped, for example, and incentives introduced to encourage landfill owners and farmers use methane to run power generators.

“Earlier studies hinted at a slowing in the long-term rise in methane--but Dlugokencky's conclusion is based on particularly frequent and accurate measurements. ‘He can connect the dots in a more accurate way than we can,’ explains David Blake. Accumulating methane is thought to prevent heat escaping from Earth into space, like the thickening blanket of carbon dioxide. It probably accounts for roughly 20% of the warming effects of greenhouse gases, compared with the 40-50% attributed to carbon dioxide.

“Human activities pump out more than two-thirds of the methane in the atmosphere, the rest comes mainly from natural wetlands. Methane survives an average of nine years in the sky before it is broken down in reactions with short-lived compounds called hydroxyl radicals. A quickening of this destruction might partly explain the methane plateau. Changes in climate can also alter the amount oozed by wetlands. ‘A collection of things has resulted in this trend,’ says Elaine Matthews, who studies methane emissions at the Goddard Institute for Space Studies at Columbia University in New York.”



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