Global warming making big impact in Hawke's Bay, says expert

12:20 PM

Global warming is having a dramatic effect on Hawke's Bay with more frequent droughts and the spread of agricultural pests, says climate scientist Jim Salinger.

"In my 25 years as a climate scientist I have been watching both global and New Zealand climate, and I have never seen such evidence of climate change as the observations coming in now," he said.

Dr Salinger, who works for the National Institute of Water and Atmospheric Research (NIWA) is not alone in this assessment.

The chair of the Intergovernmental Panel on Climate Change, Robert Watson, told the recent climate convention negotiations in The Hague that it is not a question of whether the Earth's cliamte will change, but rather by how much, how fast and where.

Dr Watson said the overwhelming majority of scientific experts believe that human-induced climate change is already occurring, and that future change is inevitable.

"If actions are not taken to reduce the projected increase in greenhouse gas emissions, the Earth's climate is likely to change at a rate unprecedented in the last 10,000 years with adverse consequences for society, undermining the very foundation of sustainable development," he said.

It is undisputed that the last two decades have been the warmest this century, and very likely the warmest for the last 1000 years, said Dr Salinger.

"It is a basic fact of physics that when the greenhouse gases of carbon dioxide and methane increase in the atmosphere, the planet will warm.

"Careful scientific measurements of amounts of these gases in our atmosphere show that carbon dioxide has risen by a third and methane more than doubled since the industrial revolution."

Sea levels are rising, rain and snowfall patterns are changing, arctic sea ice is thinnning and the frequency and intensity of El Nino events appear to be increasing.

Major heat waves, floods, droughts and other extreme weather events leading to significant loss of life and economic costs, have blasted many parts of the planet.

In New Zealand, surface air and marine temperatures have risen by almost one degree since the late 19th century.

The Southern Alps have lost about 40 per cent of their permanent snow and ice in the last 100 years.

There have been large shifts in wind and rainfall patterns during the last quarter of the 20th century.

The wet South Island West Coast has got wetter, while the north and east of the North Island got drier.

Dr Salinger said these changes are responsible for the much more frequent droughts, particularly in Gisborne and Hawke's Bay.

"Some early impacts of warming are becoming apparent.

"Agricultural pests are migrating south, for example, a beetle pest which damages tomatoes has moved from the Bay of Plenty into Hawke's Bay.

"Already subtropical grasses, once confined to frost-free areas of northern New Zealand are spreading south.

"Kiwifruit is no longer a major Northland crop, and the wine industry is now firmly established in the South Island."

Dr Salinger has spoken in the past about the need for land-based industries to develop strategies for managing climate change.

Flexible farmers could even turn some of the changes to their advantage, but, overall, global warming could blight sustainable development in many parts of the world.

The onus is on us to take action to curb greenhouse gas emissions, otherwise the human species may not be around to see in the next millennium.

The last day of 2000 brought snow, rain and very un-summerlike temperatures to some parts of Hawke's Bay.

People with views to the Ruahine Ranges awoke on New Year's Day to see the mountains topped with snow, brought by the gusty southerlies which swept through the region on December 31 and continued on January 1.

They were accompanied by thunderstorms which belted along the coast, interspersed by fine, hot sunny spells.

Napier also recorded the country's highest air temperature in December, reaching 34.4 degrees on Christmas Day.

It was the hottest December day in Napier since records began in 1868.

None of the major towns or cities in Hawke's Bay — Napier, Hastings, Wairoa, Havelock North, Dannevirke or Waipukurau - managed to make it an average year for rainfall.

None of the rainfalls reached normal levels, with Havelock in particular having less than half the usual yearly amount.

- HAWKE'S BAY TODAY