On September 25 former President Bill Clinton and former Vice-President Al Gore discussing climate change with Charlie Rose.
On September 25 former President Bill Clinton and former Vice-President Al Gore discussing climate change with Charlie Rose.
Rapidly rising carbon dioxide levels in the atmosphere are causing a potential catastrophe in our oceans as they become more acidic, scientists have warned.
Hans Poertner, professor of marine biology at the Alfred Wegener Institute in Germany, and co-author of a new study of the phenomenon, told the Guardian: "The current rate of change is likely to be more than 10 times faster than it has been in any of the evolutionary crises in the earth's history."
Seawater is naturally slightly alkaline, but as oceans absorb CO2 from the air, their pH level falls gradually. Under the rapid escalation of greenhouse gas emissions, ocean acidification is gathering pace and many forms of marine life – especially species that build calcium-based shells – are under threat.
Poertner said that if emissions continue to rise at "business as usual" rates, this would be potentially catastrophic for some species. Acidification is just one of a broader range of the problems facing the oceans and the combination of different effects is increasing the threat. Poertner said: "We are already seeing warm water coral reefs on a downslide due to a combination of various stressors, including [rising] temperature. Ocean acidification is still early in the process [but] it will exacerbate these effects as it develops and we will see more calcifying species suffering."
However, the process of acidification takes decades and the worst effects on some species could still be avoided if emissions are urgently reduced. "The ocean is changing already, mostly due to temperature – acidification will exacerbate those effects," Poertner said.
Evidence from prehistoric ocean life provides a comparison. "The [effects observed] among invertebrates resembles those seen during the Permian Triassic extinctions 250m years ago, when carbon dioxide was also involved. The carbon dioxide range at which we see this sensitivity [to acidification] kicking in are the ones expected for the later part of this century and beyond."
Oceans are one of the biggest areas of focus for current climate change research. The gradual warming of the deep oceans, as warmer water from the surface circulates gradually to lower depths, is thought to be a significant factor in the earth's climate. New science suggests that the absorption of heat by the oceans is probably one of the reasons that the observed warming in the last 15 years has been at a slightly slower pace than previously, and this is likely to form an important part of next month's Intergovernmental Panel on Climate Change (IPCC) report.
The IPCC report, the first since 2007, will provide a comprehensive picture of our knowledge of climate change. It is expected to show that scientists are at least 95% certain that global warming is happening and caused by human activity, but that some uncertainties remain over the exact degree of the planet's sensitivity to greenhouse gas increases.
The new study, entitled Inhospitable Oceans, published on Monday in the peer-review journal Nature Climate Change, was based on examinations of five key components of ocean eco-systems: corals, echinoderms, molluscs, crustaceans and fish. All were found to be adversely affected by acidification: crustaceans were more resilient, while corals, molluscs and echinoderms were worst affected. The direct effects on fish were less clear.
Astrid Wittmann, co-author of the paper, said species with low resilience could be outcompeted by those that were more vulnerable to acidification, and that further studies were needed, particularly on plants and plankton, which were left out of this research. More
I am off to Istanbul tomorrow to join the Climate Reality Leadership Corps with former Vice-President Al Gore. I want to help change the world and raise awareness of climate change. After four years of trying I have finally been invited to undertake the training.
All around the world, members of the Climate Reality Leadership Corps trained by Chairman and former Vice President Al Gore are standing up and making a difference on the climate crisis. They’re leading by example, speaking to their communities about how climate change affects their daily lives—and what we can do to solve it. They’re appearing in the media, activating social networks, and—most of all—inspiring people everywhere to join us in confronting the defining issue of our time.
I have not been in Istanbul since 1976 so it will be good to be back and revisit some of the wonderful places to see. I am staying in the old city close to the Blue Mosque. One of the other places I want to see is the Basilica Cistern given my interest in water harvesting and storage.
This cathedral-size cistern is an underground chamber approximately 138 metres (453 ft) by 64.6 metres (212 ft)[5] - about 9,800 square metres (105,000 sq ft) in area - capable of holding 80,000 cubic metres (2,800,000 cu ft) of water. The ceiling is supported by a forest of 336 marble columns, each 9 metres (30 ft) high, arranged in 12 rows of 28 columns each spaced 4.9 metres (16 ft) apart. The capitals of the columns are mainly Ionic and Corinthianstyles, with the exception of a few Doric style with no engravings. One of the columns is engraved with raised pictures of a Hen's Eye, slanted braches, and tears. This column resembles the columns of the Triumphal Arch of Theodosius I from the 4th century (AD 379-395), erected in the 'Forum Tauri' Square. Ancient texts suggest that the tears on the column pay tribute to the hundreds of slaves who died during the construction of the Basilica Cistern. The majority of the columns in the cistern appear to have been recycled from the ruins of older buildings (a process called 'spoliation'), likely brought to Constantinople from various parts of the empire, together with those that were used in the construction of Hagia Sophia. They are carved and engraved out of various types of marble and granite.[6]
Fifty-two stone steps descend into the entrance of the cistern. The cistern is surrounded by afirebrick wall with a thickness of 4 metres (13 ft) and coated with a waterproofing mortar. The Basilica Cistern's water came from the Eğrikapı Water Distribution Center in the Belgrade Forest, which lie 19 kilometres (12 mi) north of the city. It traveled through the 971 metres (3,186 ft)-long Valens (Bozdoğan) Aqueduct, and the 115.45 metres (378.8 ft)-long Mağlova Aqueduct, which was built by the Emperor Justinian.[7]
The cistern has the capacity to store 100,000 tons of water, despite being virtually empty today with only a few feet of water lining the bottom.
The weight of the cistern lies on the columns by means of the cross-shaped vaults and round arches of its roof.
The Basilica Cistern has undergone several restorations since its foundation. The first of the repairs were carried out twice during the Ottoman State in the 18th century during the reign of Ahmed III in 1723 by the architect Muhammad Agha of Kayseri. The second major repair was completed during the 19th century during the reign of Sultan Abdulhamid II (1876–1909). Cracks to masonry and damaged columns were repaired in 1968, with additional restoration in 1985 by the Istanbul Metropolitan Museum. During the 1985 restoration, 50,000 tons of mud were removed from the cisterns, and a platforms built throughout to replace the boats once used to tour the cistern. The cistern was opened to the public in its current condition on 9 September 1987. In May 1994, the cistern underwent additional cleaning.
I believe that water security is going to be a large issue in the future and have been unfertaking a sturdy of of traditional methods of harvesting and storing water, methods with do not require huge amounts of energy.