A new report by the Australia Climate Commission (ACC), The Critical Decade: Climate science, risks, and responses
(pdf), cites “overwhelming and clear” evidence the planet is warming. Melting ice caps and glaciers, a warming ocean and warming atmosphere are leading to change in the biological world.
Those observed biological changes include gene pools, species ranges, ecosystem dynamics and timing of biological patterns.
notes “the noisy, confusing ‘debate’ in the media” while scientific research on climate change “continues to advance strongly” and calls for a decarbonization of the economy by 2050, meaning carbon emissions must peak within the next few years and then go on a strong decline. The longer we wait to address those emissions, the more difficult and costly the undertaking becomes.
and global warming has its naysayers, both in public and political circles, and while knowledge within the climate research community on the climate system continues a strong advance,
attempt to intimidate climate scientists have added to the confusion in the public about the veracity of climate science.
Based on a compilation of previous and current scientific reports and analyses, The Critical Decade notes human activities such as burning of fossil fuels (coal and oil) and deforestation are triggers to a world-wide warming trend. The study notes
This is the critical decade. Decisions we make from now to 2020 will determine the severity of climate change our children and grandchildren experience.
With the past decade (2001-2010) being the warmest on record, this decade is critical and without effective action being taken, extreme weather events
and irreversible alterations to the global climate are likely, which may lead to a struggle of life as we know it.
Already the plant and animal world is responding to warmer global temperatures. In Australia, for example, native and feral animals are migrating to higher elevations in alpine regions and the black flying fox has expanded its breeding range southward. Migratory birds are arriving earlier and departing later while the large skink has begun mating earlier and staying paired longer.
Changes in Australia’s region’s sea life in relation to warming temperatures are equally noticeable. More than half of the the intertidal species along Tasmania’s east coast have shifted their distribution pattern southward. Growth rates of long-lived Pacific fish species are going through significant changes and the barrens-forming sea urchin has extended its southern range from the mainland to Tasmania.
The most noticeable Australian marine response to a changing climate is occurring on the Great Barrier Reef where eight mass bleaching events have been recorded since 1979. There were no known such events prior to that date, according to the report.
Several factors are contributors to sea-level rise and the report notes during the period between 1961-2003, about 40 percent of the rise can be attributed to thermal expansion of the ocean as it warms, about 35 percent to the melting of continental glaciers and ice caps (e.g. the Himalayan and Andean mountain glaciers), and around 25 percent from Greenland and Antarctica’s large polar ice sheets.
Should the loss of Arctic sea ice continue at its accelerated downward trend, a threshold-abrupt change is likely. When the threshold is crossed, an irreversible meltdown occurs.
report also notes the record number of hot days in Australia over the last 50 years has more than doubled, increasing the risk of heat waves, extreme fire conditions and associated deaths. It calls for immediate action, as
The risks have never been clearer and the case for action has never been more urgent.
According to the BBC
, Australia is one of the highest per capital carbon emitters in the world and the Prime Minister Julia Gillard said: “We don’t have time ... for false claims on this debate.”