|
Grendel
|
Climate change sceptics speak out
NOT everone believes in human-caused climate change. Here, some of Australia's most respected scientists have their say on this very divisive debate.
Weather balloons disprove a theory based on a guess
By Dr David Evans
ALARMIST climate theory depends in part on a plausible guess made in the early 1980s when there was insufficient data, but disproved by 1999.
Otherwise, alarmist and sceptic scientists mostly agree about how much global warming is caused by extra carbon dioxide.
The guess is that "water feedbacks" strongly amplify the warming due to extra carbon dioxide. We can calculate how much global temperature will rise if carbon dioxide levels rise by a certain amount, if the Earth does not respond in any way to being warmer.
Alarmists and sceptics agree on these calculations. But the Earth responds to being warmer by increasing rainfall and evaporation and so on. This in turn affects the temperature further, called "feeding back".
Particularly important are the feedbacks due to water in all its forms - clouds, rain, water vapour, humidity, snow, ice, and so on. Alarmists say the feedbacks triple the warming due to carbon dioxide, sceptics say they halve them.
The theoretical amplifying assumed by alarmists would, according to them, be nearly all due to extra water vapour in the atmosphere, from extra evaporation. Water vapour is a greenhouse gas, so this would further warm the planet. That extra water vapour would expand the warm, moist, lower troposphere into the cooler, dry air above it.
If that happened it would create a "hotspot" in the atmospheric warming pattern, mainly about 10km up over the tropics. All the climate models predict a prominent hotspot. But radiosonde (weather balloon) observations from 1979 to 1999, the last period of global warming, show beyond reasonable doubt that there is no hotspot. None at all.
So the alarmist climate theory is wrong: there is no extra water vapour, so the feedbacks do not amplify. The radiosonde data shocked the alarmists, who expected a hotspot to confirm their theory.
Dr David Evans was a consultant to the Australian Greenhouse Office from 1999 to 2005
THE Great Barrier Reef is just fine and threatened by nothing
By Dr Walter Starck
Water temperatures and the frequency of destructive storms are a bit below the long-term average. The coral bleaching events of 1998 and 2002 were nothing unusual.
They were simply a result of surface warming due to extended periods of calm weather when normal wave mixing ceases.
This often happens in El Nino events.
Rapid recovery from these and more recent storm damage attests to the healthy vigour of the reef system. Run-off of agrichemicals and fertilisers is at lower levels than those in our own drinking water and has declined, not increased, over recent decades.
Of the more than 2500 reefs in the Great Barrier Reef complex, about two dozen are regularly used for tourism and 90 per cent rarely or never experience a human presence.
The commercial fishing catch is restricted to a level that equates to an average harvest level of 9kg/square km/year when 4000kg is considered a conservative estimate of sustainable yield for reef fisheries.
Globally, atmospheric and ocean temperatures as well as sea level rise have all declined over the past decade.
Antarctic sea ice extent is at all-time highs. Record and near-record cold had been recorded in many areas around the world over the past few years. Record extreme high temperatures on all continents save one were between 1881 and 1942. The exception is Antarctica in 1974.
Dr Walter Starck received a PhD in marine science from the University of Miami in 1964 and was a pioneer in coral reef science. He has lived in Far North Queensland studying the Great Barrier Reef since 1978
|
Forum
Pages: 1
Alarmists rule... lets all hope not. (Read 869 times)
