Sunday, October 30, 2005

Amazon source at 36 year low

Key points

  • Worst drought in 42 years prompts declaration of State of Emergency in Amazon River delta.
  • 1000's of towns and villages cut off from outside world as falling water levels make river unnavigable.
  • The level of the tributary Rio Negro, has dropped 12 metres since July to just 16 metres.

Is this linked to global warming? Carlos Rittl, Greenpeace Brazil's climate campaigner says 'yes':

Greenpeace blames deforestation and climate change for the drought. "The Amazon is caught between these two destructive forces, and their combined effects
threaten to flip its ecosystems from forest to savannah," Mr Rittl said
Even if the drought is not a result of GW it will certainly contribute to it, given that a lot of sunk carbon in the form of biomass, ecosystems and food-chains threatens to be released into the atmosphere.
To make matters worse, as the rainforest becomes increasingly dry, damaging wildfires are regularly breaking out across the region, destroying trees.
Reference: The Sun-Herald, Oct 30, 2005: Mighty Amazon close to running out of water

Technorati Tags , , ,

Wednesday, October 26, 2005

Oceans reservoir for earth's heat energy.

A recent history of GW science.

If James E. Hansen of the NASA Goddard Institute for Space Studies in New York was right in 1997 saying that the earth is absorbing about 0.5 watt per square meter of sunlight more than it is emitting back to space, then where is the heat going? Hansen speculated it was probably in the oceans. Support came in 2000 from Sydney Levitus of the National Oceanographic Data Center in Silver Spring, Md:
That knowledge inspired Levitus and his colleagues seven years ago to launch a United Nations-sponsored global search?and-rescue operation for ocean data. The team?s primary goal was to dig up every single temperature measurement they could find for the top 3,000 meters of the ocean, enough water to engulf a skyscraper seven times as tall as the World Trade Center. They knew that the deeper they looked, the more convincing any emerging temperature trends would be.
Numbers came in from all over the world. When the British Royal Navy told Levitus that it had hundreds of thousands of index cards of hand-written temperature profiles stashed away in a musty basement, the oceanographer jumped at the chance to add them to his growing database. He didn?t have to go far. Officials loaded a ship with some 100 metal file drawers full of the cards and sent them across the Atlantic. His team also uncovered unexpected measurements from World War II at the Scripps Institution of Oceanography in San Diego and rare numbers from the icy seas around Russia and Norway in an obsure book tucked away in the New York Public Library.

When they put the millions of numbers they gathered together with several million more that already existed, they discovered that the Pacific, Atlantic and Indian oceans combined warmed an average of 0.06 degree Celsius between 1955 and 1995.
What?s more, that amount of warming accounts for a majority of Hansen?s "missing heat."

Reference: April 17, 2000

# 1 link added: terry*

* in which we have chosen the name "Terry" for our website. In case you are wondering, it is an affectionate term for the word "Terra."

This great Canadian site aims to combine art, news and geo-science. I am pleased for it to be my first link. Terry recently updated with an informative article on the developing field of Climate Modeling; what it is and why it is important.

Global warming is happening. Are we to blame or is it a natural
warming trend? Is reducing our CO2 emissions going to have any effect on
dampening this process or is it too late? How much is the earth?s temperature
going to increase in the next century and will the earth be inhabitable for
anything more than cockroaches? Climate modeling has the potential to answer
these questions. It is even more important given the influence the scientific
community can and does have on government decision making. To combat global
warming tough decisions need to be made by policy makers that may involve
sacrificing short term benefit for long term gain. Policy makers, though, are
responsible for the well being of their constituents and will only make these
tough decisions if they are given valid scientific evidence that shows the dire
consequences of not acting now. This is what climate modeling is attempting to

With the economic livelihood of a good portion of the earth?s population relying on the production and consumption of fossil fuels there are a lot of questions to be answered. One thing is certain, Climate Modeling has a big future.

Tuesday, October 25, 2005

Gums have reason to be blue

Yesterday's article prompted this creative solution to the drought in today's SMH Letters To The Editor.

Down with those gums

Given the reported link between vegetation clearing, urban sprawl and thunderstorms ("City climate surprise - trees cut, storms grow", October 24), can I suggest we tear down those pesky gum trees and whack a few new suburbs in the Blue Mountains National Park, thereby guaranteeing that when it rains it finally does so over the catchment area?

Stephen Driscoll Carlingford

Technorati Tags , , ,

Monday, October 24, 2005

Research: Sydney southwesterlys gather speed over tree-free west.

"We think the removal of the forest in western Sydney has allowed storms to move across a little quicker."

Macquarie University physical geography department researchers Professor Andy Pitman and his student colleague, Anna Gero, have discovered that their computer simulations of Sydney weather patterns with and without the original vegetation cover suggest that the changing landscape and specifically the western urban sprawl is also responsible for increasing the violence of some storms.

It also appeared the vegetation loss had changed the dynamics of atmospheric convection, which is a key to forming many thunderstorms that strike Sydney on summer days. Without the vegetation, sea breezes could sweep further inland, changing the location where they collided with winds blowing from the south-west. The biggest storms in the simulations formed over the central business district. Professor Pitman said they first thought the storms were being powered by turbulence caused by city buildings, "but we found it was really the cleared space south of Sydney".

The weather bureau's NSW regional director, Stephen Lellyett, said: "Upon a cursory examination, [the] work is very interesting - it appears plausible that the speed and intensity of systems tracking south-west to north-east could be modified by changes to the behaviour of the sea breeze and be a result of land-use change."
Ok, but how is this on-topic? I do observe how Sydney storms seem to be getting worse and had quietly wondered whether this was due to global warming, greenhouse gas style. If Professor Andy Pitman and his student colleague are right it is good news. The increasing serverity of storms has localised causes, at least to some extent. Re-treeing the backyards, parklands and open spaces of western Sydney could help create a storm-break that will help reduce the severity of our storms.

Technorati Tags , ,

Sunday, October 23, 2005

Blame it on The Weather Makers

Read the book! Stirred to curiosity by a review on ABC Radio I did something I haven't done for a long time. I bought a book, to read, for me.

It didn't disappoint. Tim Flannery's The Weather Makers is riveting, clarifying and horrifying. After finishing it I loaned it to Pip, my neighbour, who is a communications consulant for the environmental industry, or I would give you a critique. Suffice to say, the controversies it raises have prompted me to start this blog to explore the issues further. Later though. Now I sleep.