Tag Archives: sea levels
Researchers at the UK's National Oceanography Centre in Southampton have found that greenhouse gas concentrations similar to the present have been associated with sea levels at least nine metres above current levels. The researchers compiled more than two thousand pairs of CO2 and sea level data points, spanning critical periods within the last 40 million years. They used these values to find the "natural equilibrium" sea level for CO2 concentrations ranging between values of 180 parts per million and more than 1,000 parts per million. For values between 400 and 450 parts per million – which is the target range … Continue Reading
U.S. scientists using satellite data have established a more accurate figure of the amount of annual sea level rise from melting glaciers and ice caps. There are more than 160,000 glaciers and ice caps worldwide but annual changes in mass have been directly measured for only 120 of them and, in most cases, only within the last 30 years. For the first time, researchers used the GRACE (for "Gravity Recovery and Climate Experiment") satellite system, operated by NASA and Germany, to look at loss of ice by all glaciers and ice caps around the world. Data, collected for the years … Continue Reading
In 2007, the IPCC projected a maximum sea level rise of 59 centimetres by 2100. The IPCC acknowledged that this was likely to be an under-estimate because understanding of the processes happening on ice sheets was inadequate to enable reliable estimates to be made. A team of researchers led by Eric Rignot from Nasa’s Jet Propulsion Laboratory has now reported that ice loss from Antarctica and Greenland has accelerated over the last 20 years and the increase in sea levels will, indeed, be significantly higher than the 2007 estimate.
Until now, it had been thought that melting ice could form a slippy layer at the bottonm of the Greenland ice sheet causing it to slide rapidly into the sea. Now, a study by Professor Andrew Shepherd of the University of Leeds, has shown that this is not happening. Professor Shepherd’s team used satellite imagery to track the progress of the west Greenland ice sheet each summer, over five years. They found that, above a certain threshold, the slipping begins to slow. On-the-ground studies and work done on alpine glaciers suggests that higher volumes of meltwater actually forms channels under … Continue Reading
There have been several estimates that Greenland is shedding roughly 230 billion tonnes of ice and West Antarctica around 132 billion tonnes per year and analysts have been concerned that these rates are much faster than predicted by climate models – suggesting that the models may be far too conservative. Now researchers from the US Jet Propulsion Laboratory, the Technical University of Delft and SRON Netherlands Institute for Space Research have published research which corrects that estimate for deformation processes occurring in the Earth’s crust. The researchers used GPS and sea floor pressure measurements to estimate the movement of the … Continue Reading
For years, we have been warned that low-lying coral island states will be drowned by rising sea levels. Now the first analysis of the data broadly suggests the opposite – most have remained stable, while some have even grown, despite rising sea levels, over the last 60 years. Nanumea Atoll, Tuvalu (NASA image) Paul Kench at the University of Auckland in New Zealand and Arthur Webb at the South Pacific Applied Geoscience Commission in Fiji used historical aerial photos and high-resolution satellite images to study changes in the land surface of 27 Pacific islands over the last 60 years. Local … Continue Reading
There have been many claims that the Pacific Island nation of Tuvalu is drowning because of rising seas resulting from climate change. Tuvalu is a group of nine small islands with a total area of 26 square kilometres and a population of about 12,000. Its average height above sea level is just 3 metres. Tuvalu has no fresh water streams, no known mineral resources, poor soil, declining vegetation because of excessive clearing and almost no exports. Tuvalu – Funafuti – Approach (by mrlins ex Flickr) In 2000, the University of Hawaii conducted a study which concluded that over the previous … Continue Reading
It is certainly true that sea levels are rising – they have been for the last 18,000 years. Since the peak of the last ice age 18.000 years ago, seas have risen by 130 metres. During the current interglacial period, sea levels were at their highest about 140,000 years ago when they were briefly 6 metres higher than now. They have been higher in the far distant past but changed landforms make comparisons meaningless. For most of the last 3,000 years, seas have been rising at between 1 and 2 millimetres a decade. Since 1900, the rate of sea level … Continue Reading
Videos
Renewables News- Vic Council Approves Wind Farm with Community SharesBuloke Shire has approved a planning permit for a five-turbine wind farm spanning 5.t hectares at Coonooer Bridge, west of Bendigo..It is the first wind farm planning permit approved since 2011 when the Victorian Government introduced tough planning laws that … Continue Reading → […]
- NZ Electricity Co Offers Solar PV with BatteryVector Limited, the largest electricity and gas distribution company in New Zealand, is offerring a "home solar power solution", incorporating intelligent battery storage into a traditional solar PV system. In the introductory phase of the programme, a limited number of … Continue Reading → […]
- Sydney City Revises Trigen Power PlanThe City of Sydney has decided not to pursue its plan for a trigeneation power precinct at Green Square at this time but has re-affirmed its commitment to cutting carbon emissions using trigeneration, among other technologies, The decision to halt … Continue Reading → […]
- Vic Council Approves Wind Farm with Community Shares
