Our Planet Hottest Since Human Civilisation

Earth is on track to becoming the hottest it has been at any time in the past 11.3 millennia, a period spanning the history of human civilisation, a new study says.

Based on fossil samples and other data collected from 73 sites around the world, scientists have been able to reconstruct the history of the planet’s temperature from the end of the last Ice Age around 11,000 years ago to the present.

They have determined the past 10 years have been hotter than 80 per cent of the past 11,300 years.

However virtually all the climate models evaluated by the Intergovernmental Panel on Climate Change predict Earth’s atmosphere will be hotter in the coming decades than at any time since the end of the Ice Age.

This finding is resolute no matter what greenhouse gas emission scenario is used, the study found :: Read the full article »»»»

Antarctic Ice Sheets Melting Faster Than Previously Thought

A study of temperature records over more than half a century shows the west Antarctic ice sheet is warming nearly twice as quickly as previously thought.

A re-analysis of temperature records from 1958 to 2010 revealed an increase of 2.4 degrees Celsius over the period, three times the average global rise.

The increase means west Antarctica is one of the fastest-warming regions on Earth, according to paper co-author David Bromwich of the Byrd Polar Research Centre.

“Records suggests that continued summer warming in west Antarctica could upset the surface balance of the ice sheet, so that the region could make an even bigger contribution to sea-level rise than it already does.” David Bromwich said :: Read the full article »»»»

Southern Ocean Carbon NOT Sinking

Australian and British researchers have found that one of the world’s largest carbon sinks stores carbon differently than first thought. Utilising data collected over ten years from robotic – Argo – probes, the team has shown subduction happens at specific locations as a result of interplay between winds, currents and massive whirlpools.

Dr Matear says the study also shows the Southern Ocean is not as efficient as first thought in capturing anthropogenic carbon dioxide. The Southern Ocean contains about 40 per cent of all carbon dioxide emissions absorbed by the world’s oceans.

Researchers from the CSIRO and British Antarctic Survey examined the way the Southern Ocean sucks carbon absorbed from the surface layer into the deeper ocean.

Research co-author Dr Richard Matear from the CSIRO says the study shows the method through which carbon is drawn down from the surface of the Southern Ocean to the ocean’s interior – or deep waters :: Read the full article »»»»

El Nino Tipped to Form in Spring

ABC.net.au‘s Will Ockenden has a superlative piece on the guessing game that is The Australian Weather. 

Australia looks set to experience the same weather conditions this year that were responsible for the nation’s last devastating drought in the summer of 2009.

The weather bureau say all of its models are pointing to an El Nino weather system forming in October.

Typically, El Nino weather events mean drier conditions across Australia, and despite the plentiful rain along the east coast over the past week, there are still large areas of the country that still have below-average rainfall.

Earlier this year, Australia had been experiencing the La Nina climate pattern, leading to wetter weather.

El Nino occurs when the central and eastern Pacific warms up, causing major shifts in weather patterns :: Read Ockenden’s full article at abc.net.au  »»»»

Sauropod Flatulence Caused Mesozoic Climate Change

We’ve all heard the – possibly dubious – theory that bovine flatulence is adding to global warming? If not, the theory goes something like…

The abundance of methane evacuated from bovine rectum is apparently taken so seriously that in 2008 - at the height of greenhouse panic – the head of the international panel advising the world’s governments on how to reduce global emissions says people should stop eating red meat.

With cattle population sitting around 1.9 billion, cattle flatus accounts for about 30 per cent of the methane in the atmosphere, according to the US EPA, thats about 80 million metric tonnes a year, eeeew…

According to researchers, this isn’t the first time the planet has faced this particular problem. Researchers say dinosaur flatulence could have put enough methane into the atmosphere to warm the planet during the hot, wet Mesozoic era :: Read the full article »»»»

Wind Farms Linked to Localised Climate Change

Turbulence created by wind farms causes air temperatures to rise directly around the supposed green energy producers, researchers say. Scientists including Associate Professor Liming Zhou from the State University of New York examined conditions around 2,358 turbines at four Texas wind farms.

Writing in the journal Nature Climate Change, Professor Zhou and colleagues reported a temperature increase of up to 0.72 degrees Celsius per decade at wind farm locations, compared to nearby areas. The wind industry in the United States has experienced a remarkably rapid expansion of capacity in recent years and this fast growth is expected to continue in the future.

While converting wind’s kinetic energy into electricity, wind turbines modify surface–atmosphere exchanges and the transfer of energy, momentum, mass and moisture within the atmosphere. These changes, if spatially large enough, may have noticeable impacts on local to regional weather and climate.

Oddly, researchers also found the effect to be greater at night than during the day. After discounting the impact of surface features such as vegetation, roads, light reflection and surface structures, the researchers concluded that the temperature change was caused by air turbulence generated by the turbines’ giant rotor blades. Professor Zhou said the study could help researchers better understand the impact of wind farms on local environments :: Read the full article »»»»

Our Planet’s Water Cycle is Intensifying With Global Warming

A study published in the journal Science has concluded that climate change is altering oceans and rainfall worldwide. A team of three researchers looked at ocean data over the period 1950 to 2000. The research found salinity levels have changed in all the world’s oceans, wetter areas are experiencing more rain and drier areas have become drier.

Susan Wijffels from the Commonwealth Scientific and Industrial Research Organisation – CSIRO - says she expects the trend to continue.

“The answer of how much more is going to be in the future depends on how much more warning there is going to be,” she said. ”So if we stay on a high emissions pathway we might see warming up around three degrees, which will give us maybe a 24 per cent change in our water cycle.”

The authors say this could have implications for global food security. In the paper, Australian scientists from the CSIRO and the Lawrence Livermore National Laboratory, California, reported changing patterns of salinity in the global ocean during the past 50 years, marking a clear fingerprint of climate change. :: Read the full article »»»»