Freeman Dyson says he doesn’t want his legacy to be defined by climate change, but his dissension from the orthodoxy of global warming is significant because of his stature and his devotion to the integrity of science. Read more here.
Archives for April 2009
The Importance of Sceptism
A society will only be able to benefit from science if it can sustain a sceptical outlook as part of its inherent cultural fabric. Janet Barlow.
Deep Solar Minimum
The sunspot cycle is behaving a little like the stock market. Just when you think it has hit bottom, it goes even lower. Read more here.
A Reality Check on the Role of Water Vapour in Climate Change: A Note from Michael Hammer
ACCORDING to the international panel on climate change (IPCC) any direct temperature rise from increasing carbon dioxide levels is greatly amplified by positive feedback from water vapour. As the theory goes, rising carbon dioxide levels from human activity causes some temperature rise which causes more water to evaporate. Because water vapour is the dominant greenhouse gas, the additional water vapour absorbs even more energy, so global temperatures rise even, more causing still more water to evaporate and so on in an amplifying spiral. In this way the roughly half degree direct impact from doubling carbon dioxide is claimed to be amplified to three degrees or more.
An interesting theory, but now consider the following scenario;
We know the earth rotates about an axis tilted about 23 degrees relative to the sun. This is what causes the seasons and what sets the Tropics of Cancer and Capricorn. Imagine a location on the Tropic of Capricorn (23 degrees south) – say Mackay in Queensland. In summer the sun is directly overhead – average solar input of around 310 watts/sq meter. In winter the sun is at maximum elevation 44 degrees – average solar input of around 220 watts/sq meter. That is a difference summer to winter of about 90 watts/sq meter which, according to Stefan’s law, without any feedbacks would give a temperature difference summer to winter of about 16 degrees. The amount of positive or amplifying feedback claimed by the IPCC would inflate that about 6 times to more than 90 degrees C, extinguishing all life in Mackay.
Native Ants Kill Cane Toads
ECOLOGISTS in Australia have discovered that cane toads are susceptible to being killed and eaten by meat ants – and much more susceptible to the ants than are native Australian frogs.
They claim that their research – published in the British Ecological Society’s journal Functional Ecology – reveals a “chink in the cane toad’s armour” that could help control the spread of this alien invasive species in tropical Australia.
Professor Rick Shine and his colleagues Georgia Ward-Fear, Matt Greenlees and Greg Brown from the University of Sydney’s Team Bufo (from the Latin name for the toxic toad) compared habitat use and activity patterns in meat ants, metamorph cane toads and seven native Australian frog species. They found that, unlike the native frogs, cane toads are poorly equipped to escape the meat ants.
No Dust, Warms Atlantic Ocean?
According to a new study, about 70% of the recent warming trend in the Atlantic Ocean is from reduced numbers of dust storms and volcanic eruptions. Other factors, such as a warming of the global climate, contribute only about 30% to the upward trend. Read more here.
Jennifer Marohasy BSc PhD has worked in industry and government. She is currently researching a novel technique for long-range weather forecasting funded by the B. Macfie Family Foundation.