“Climate change may be far worse than scientists thought, causing global temperatures to rise by at least 4 degrees Celsius by 2100, or about 7.2 degrees Fahrenheit, according to a new study.
The study, published in the journal Nature, takes a fresh look at clouds’ effect on the planet, according to a report by The Guardian. The research found that as the planet heats, fewer sunlight-reflecting clouds form, causing temperatures to rise further in an upward spiral.
That number is double what many governments agree is the threshold for dangerous warming. Aside from dramatic environmental shifts like melting sea ice, many of the ills of the modern world — starvation, poverty, war and disease — are likely to get worse as the planet warms.
“4C would likely be catastrophic rather than simply dangerous,” lead researcher Steven Sherwood told the Guardian. “For example, it would make life difficult, if not impossible, in much of the tropics, and would guarantee the eventual melting of the Greenland ice sheet and some of the Antarctic ice sheet.”
Another report released earlier this month said the abrupt changes caused by rapid warming should be cause for concern, as many of climate change’s biggest threats are those we aren’t ready for.”
“Climate change is causing the North Pole’s location to drift, owing to subtle changes in Earth’s rotation that result from the melting of glaciers and ice sheets.
…Computer simulations had suggested that the melting of ice sheets and the consequent rise in sea level could affect the distribution of mass on the Earth’s surface. This would in turn cause the Earth’s axis to shift, an effect that has been confirmed by measurements of the positions of the poles.
…Jianli Chen of the University of Texas at Austin and colleagues have shown that melting due to our greenhouse-gas emissions is making its own contribution to the shift. …”Ice melting and sea level change can explain 90 per cent of the [eastward shift],” says Chen. “The driving force for the sudden change is climate change.””
“…a group of researchers from Harvard and Oregon State University has published the first global temperature reconstruction for the last 11,000 years – that’s the whole Holocene (Marcott et al. 2013). The results are striking…
Over the last decades, numerous researchers have painstakingly collected, analyzed, dated, and calibrated many data series that allow us to reconstruct climate before the age of direct measurements. Such data come e.g. from sediment drilling in the deep sea, from corals, ice cores and other sources. Shaun Marcott and colleagues for the first time assembled 73 such data sets from around the world into a global temperature reconstruction for the Holocene, published in Science. Or strictly speaking, many such reconstructions: they have tried about twenty different averaging methods and also carried out 1,000 Monte Carlo simulations with random errors added to the dating of the individual data series to demonstrate the robustness of their results.
To show the main result straight away, it looks like this:
Figure 1 Blue curve: Global temperature reconstruction from proxy data of Marcott et al, Science 2013. Shown here is the RegEM version – significant differences between the variants with different averaging methods arise only towards the end, where the number of proxy series decreases. This does not matter since the recent temperature evolution is well known from instrumental measurements, shown in red (global temperature from the instrumental HadCRU data). Graph: Klaus Bitterman.
The climate curve looks like a “hump”. At the beginning of the Holocene – after the end of the last Ice Age – global temperature increased, and subsequently it decreased again by 0.7 ° C over the past 5000 years. The well-known transition from the relatively warm Medieval into the “little ice age” turns out to be part of a much longer-term cooling, which ended abruptly with the rapid warming of the 20th Century. Within a hundred years, the cooling of the previous 5000 years was undone.”
Read more: http://www.realclimate.org/index.php/archives/2013/09/paleoclimate-the-end-of-the-holocene/
“The Arctic has warmed twice as fast as the rest of the globe in the past two decades. Sea ice in this region is melting into the ocean so rapidly that its rate exceeds most model projections. The consequences of a world with less sea ice, argue the authors of this Review, include amplification of the warming phenomenon: less sea ice means fewer surfaces to reflect sun back into the atmosphere. Thus, loss of sea ice is not just an indicator of warming, but a contributor to it as well.
Read more about this research from the 2 August issue of Science here.”
“Climatologist Jason Box has a radical theory why…
In 2009, he announced the Petermann glacier, one of the largest in Greenland, would break up that summer – a potent sign of how fast the Arctic was warming. Most glaciologists thought he was nuts – especially after the summer passed and nothing happened. In 2010, however, Petermann began to calve; two years later, it was shedding icebergs twice the size of Manhattan. Another example: In early 2012, Box predicted there would be surface melting across the entirety of Greenland within a decade. Again, many scientists dismissed this as alarmist claptrap. If anything, Box was too conservative – it happened a few months later. He also believes that the climate community is underestimating how much sea levels could rise in the coming decades.
…Box decided to return to Greenland this summer – his 24th trip here in the past 20 years – to test a more startling hypothesis, part of what he calls “a unified theory” of glaciology: that tundra fires in Canada, massive wildfires in Colorado and pollution from coal-fired power plants in Europe and China had sent an unexpectedly thick layer of soot over the Arctic region last summer, which settled onto Greenland’s vast frozen interior, increasing the amount of sunlight the snow and ice absorbed, which in turn accelerated the melting.”