July 2015 was warmest month ever recorded for the globe

The July average temperature across global land and ocean surfaces was 1.46°F (0.81°C) above the 20th century average. As July is climatologically the warmest month for the year, this was also the all-time highest monthly temperature in the 1880-2015 record, at 61.86°F (16.61°C), surpassing the previous record set in 1998 by 0.14°F (0.08°C).

July 2015 Blended Land and Sea Surface 
[Credit: NOAA]

Separately, the July globally-averaged land surface temperature was 1.73°F (0.96°C) above the 20th century average. This was the sixth highest for July in the 1880-2015 record.

The July globally-averaged sea surface temperature was 1.35°F (0.75°C) above the 20th century average. This was the highest temperature for any month in the 1880-2015 record, surpassing the previous record set in July 2014 by 0.13°F (0.07°C). The global value was driven by record warmth across large expanses of the Pacific and Indian Oceans.

The average Arctic sea ice extent for July was 350,000 square miles (9.5 percent) below the 1981-2010 average. This was the eighth smallest July extent since records began in 1979 and largest since 2009, according to analysis by the National Snow and Ice Data Center using data from NOAA and NASA.

Antarctic sea ice during July was 240,000 square miles (3.8 percent) above the 1981-2010 average. This was the fourth largest July Antarctic sea ice extent on record and 140,000 square miles smaller than the record-large July extent of 2014.

Temperature Percentiles July 2015 Blended Land & Sea Surface
 Temperature Anomalies in °C [Credit: NOAA]

Global highlights: Year-to-date (January-July 2015)

• The year-to-date temperature combined across global land and ocean surfaces was 1.53°F (0.85°C) above the 20th century average. This was the highest for January-July in the 1880-2015 record, surpassing the previous record set in 2010 by 0.16°F (0.09°C).

• The year-to-date globally-averaged land surface temperature was 2.41°F (1.34°C) above the 20th century average. This was the highest for January-July in the 1880-2015 record, surpassing the previous record of 2007 by 0.27°F (0.15°C).

• The year-to-date globally-averaged sea surface temperature was 1.21°F (0.67°C) above the 20th century average. This was also the highest for January-July in the 1880-2015 record, surpassing the previous record of 2010 by 0.11°F (0.06°C). Every major ocean basin observed record warmth in some areas.

See the full report here.

Source: National Oceanic and Atmospheric Administration [August 21, 2015]

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Europe hit by one of the worst droughts since 2003

Much of the European continent has been affected by severe drought in June and July 2015, one of the worst since the drought and heat wave of summer of 2003, according to the latest report by the JRC's European Drought Observatory (EDO). The drought, which particularly affects France, Benelux, Germany, Hungary, the Czech Republic, northern Italy and northern Spain, is caused by a combination of prolonged rain shortages and exceptionally high temperatures.

Many parts of the European continent are experiencing one of the worst
 droughts since 2003 [Credit: © Fotolia, Photoman]

Satellite imagery and modelling revealed that the drought, caused by prolonged rainfall shortage since April, had already affected soil moisture content and vegetation conditions in June. Furthermore, the areas with the largest rainfall deficits also recorded exceptionally high maximum daily temperatures: in some cases these reached record values.

Another characteristic of this period was the persistence of the thermal anomalies: in the entire Mediterranean region, and particularly in Spain, the heat wave was even longer than that of 2003, with maximum daily temperatures consistently above 30°C for durations of 30 to 35 days (even more than 40 days in Spain).

Areas with the lowest soil moisture content since 1990 in July 2015 (in red) and
 in July 2003 (in blue) [Credit: JRC-EDEA database (EDO). © EU, 2015]

While sectors such as tourism, viticulture and solar energy benefited from the unusual drought conditions, many environmental and production sectors suffered due to water restrictions, agricultural losses, disruptions to inland water transport, increased wildfires, and threats to forestry, energy production, and human health.

Rainfall is urgently needed in the coming months to offset the negative impacts of the 2015 drought situation. The current seasonal weather forecast envisages more abundant rains for the Mediterranean region in September, but no effective improvement is yet foreseen for parts of western, central and eastern Europe.

Source: European Commission, Joint Research Centre [August 21, 2015]

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Boreal forests challenged by global change

Management of boreal forests needs greater attention from international policy, argued forestry experts from the International Institute for Applied Systems Analysis (IIASA), Natural Resources Canada, and the University of Helsinki in Finland in a new article published this week in the journal Science. The article, which reviews recent research in the field, is part of a special issue on forests released in advance of the World Forestry Congress in September.

Taiga Landscape in Quebec, Canada, dominated by Black Spruce Picea mariana 
[Credit: WikiCommons]

"Boreal forests have the potential to hit a tipping point this century," says IIASA Ecosystems Services and Management Program researcher Anatoly Shvidenko. "It is urgent that we place more focus on climate mitigation and adaptation with respect to these forests, and also take a more integrated and balanced view of forests around the world."

Boreal forests, which sprawl across the northernmost regions of Canada, Russia, Alaska, and Scandinavia, make up about 30% of total forest area on the planet. They play a vital role in Earth's climate system by sequestering carbon dioxide from the atmosphere. They are home to a plethora of plants and animals. And they provide resources including substantial amounts of wood for lumber and biofuel production, as well as economic and resource opportunities for local and indigenous people.

At the same time, boreal forests are one of the ecosystems most affected by climate change, with temperatures in the arctic and boreal domains recently warming at rates as high as 0.5°C per decade, and potential future warming of 6 to 11°C over vast northern regions by 2100, according to the IPCC's most pessimistic scenario, RCP 8.5.

Studies have shown that climate zones in boreal forests are moving northwards ten times faster than the trees' ability to migrate. Warmer and drier conditions and enhanced variability of climate may have already contributed to increased extent of wildfires, and the spread of outbreaks of dangerous insects. Thawing permafrost poses threats to the hydrological system at the continental scale, as well as the potential of releasing huge amounts of CO2 and methane. Locally, increasing non-forestry industrial development, accompanied by air pollution, soil and water contamination, might reinforce the negative impacts of climate change. Overall, these factors mean that huge areas of boreal forest will be at high risk of impoverishment or change to grassland or shrubland.

"These forests evolved under cold conditions, and we do not know enough about the impacts of warming on their resilience and buffering capacity," says Shvidenko.

In the article, the researchers call for governments and societies to place greater focus on the health of boreal forests, meaning the forests' resilience, adaptive capacity, and productivity. Transition to adaptive forest management is an urgent need for securing future sustainable development of boreal forests. They also stress the key role of monitoring and research to continuously assess the state of boreal forests and improve the understanding of feedbacks and interactions in order to decrease the risk of catastrophic tipping points, where the forests switch from being a net sink for CO2 to a major source of increased greenhouse gas emissions.

Source: International Institute for Applied Systems Analysis [August 21, 2015]

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Without humans, the whole world could look like Serengeti

The fact that the greatest diversity of large mammals is found in Africa reflects past human activities -- and not climatic or other environmental constraints. This is determined in a new study, which presents what the world map of mammals would look like if modern man (Homo sapiens) had never existed.

The natural diversity of large mammals is shown as it would appear without the impact
 of modern man (Homo sapiens). The figure shows the variation in the number
 of large mammals (45 kg or larger) that would have occurred per 100 x 100 
kilometer grid cell. The numbers on the scale indicate the 
number of species [Credit: Soren Faurby]

In a world without humans, most of northern Europe would probably now be home to not only wolves, Eurasian elk (moose) and bears, but also animals such as elephants and rhinoceroses.

This is demonstrated in a new study conducted by researchers from Aarhus University, Denmark. In a previous analysis, they have shown that the mass extinction of large mammals during the Last Ice Age and in subsequent millennia (the late-Quaternary megafauna extinction) is largely explainable from the expansion of modern man (Homo sapiens) across the world. In this follow-up study, they investigate what the natural worldwide diversity patterns of mammals would be like in the absence of past and present human impacts, based on estimates of the natural distribution of each species according to its ecology, biogeography and the current natural environmental template. They provide the first estimate of how the mammal diversity world map would have appeared without the impact of modern man.

"Northern Europe is far from the only place in which humans have reduced the diversity of mammals -- it's a worldwide phenomenon. And, in most places, there's a very large deficit in mammal diversity relative to what it would naturally have been," says Professor Jens-Christian Svenning, Department of Bioscience, Aarhus University, who is one of the researchers behind the study.

Africa is the last refuge

The current world map of mammal diversity shows that Africa is virtually the only place with a high diversity of large mammals. However, the world map constructed by the researchers of the natural diversity of large mammals shows far greater distribution of high large-mammal diversity across most of the world, with particularly high levels in North and South America, areas that are currently relatively poor in large mammals.

The current diversity of large mammals is shown. It can clearly be seen that large
 numbers of species virtually only occurs in Africa, and that there are generally
 far fewer species throughout the world than there could have been
[Credit: Soren Faurby]

"Most safaris today take place in Africa, but under natural circumstances, as many or even more large animals would no doubt have existed in other places, e.g., notably parts of the New World such as Texas and neighboring areas and the region around northern Argentina-Southern Brazil. The reason that many safaris target Africa is not because the continent is naturally abnormally rich in species of mammals. Instead it reflects that it's one of the only places where human activities have not yet wiped out most of the large animals," says Postdoctoral Fellow Soren Faurby, Department of Bioscience, Aarhus University, who is the lead author on the study.

The existence of Africa's many species of mammals is thus not due to an optimal climate and environment, but rather because it is the only place where they have not yet been eradicated by humans. The underlying reason includes evolutionary adaptation of large mammals to humans as well as greater pest pressure on human populations in long-inhabited Africa in the past.

Better understanding helps nature preservation

The study's openly accessible data set of natural range maps for all late-Quatenary mammals provides researchers with the first opportunity to analyse the natural patterns in the species diversity and composition of mammals worldwide. Hereby, it can be used to provide a better understanding of the natural factors that determine the biodiversity in a specific area.

Today, there is a particularly large number of mammal species in mountainous areas. This is often interpreted as a consequence of environmental variation, where different species have evolved in deep valleys and high mountains. According to the new study, however, this trend is much weaker when the natural patterns are considered.

"The current high level of biodiversity in mountainous areas is partly due to the fact that the mountains have acted as a refuge for species in relation to hunting and habitat destruction, rather than being a purely natural pattern. An example in Europe is the brown bear, which now virtually only live in mountainous regions because it has been exterminated from the more accessible and most often more densely populated lowland areas," explains Soren Faurby.

Hereby, this new study can provide an important base-line for nature restoration and conservation.

The study has been published in the scientific journal Diversity and Distributions.

Source: Aarhus University [August 20, 2015]

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The unique ecology of human predators

Are humans unsustainable 'super predators'? Want to see what science now calls the world's "super predator"? Look in the mirror.

Big game hunter Gary Kock and 'prize' 
[Credit: The Greanville Post]

Research published today in the journal Science by a team led by Dr. Chris Darimont, the Hakai-Raincoast professor of geography at the University of Victoria, reveals new insight behind widespread wildlife extinctions, shrinking fish sizes and disruptions to global food chains.

"These are extreme outcomes that non-human predators seldom impose," Darimont's team writes in the article titled "The Unique Ecology of Human Predators."

A coastal wolf is hunting salmon in British Columbia, Canada 
[Credit: Guillaume Mazille]

"Our wickedly efficient killing technology, global economic systems and resource management that prioritize short-term benefits to humanity have given rise to the human super predator," says Darimont, also science director for the Raincoast Conservation Foundation. "Our impacts are as extreme as our behaviour and the planet bears the burden of our predatory dominance."

The team's global analysis indicates that humans typically exploit adult fish populations at 14 times the rate of marine predators. Humans hunt and kill large land carnivores such as bears, wolves and lions at nine times the rate that these predatory animals kill each other in the wild.

Wildlife under pressure. Darimont et al. show that the rates at which humans exploit 
land mammals and marine fish vastly exceeds the impacts of other predators. 
Marine fish experience “fishing through marine food webs,” with different trophic 
groups similarly affected. In contrast, on land top predators are exploited at 
much higher rates than are herbivores [Credit: P. Huey/Science]

Humanity also departs fundamentally from predation in nature by targeting adult quarry. "Whereas predators primarily target the juveniles or 'reproductive interest' of populations, humans draw down the 'reproductive capital' by exploiting adult prey," says co-author Dr. Tom Reimchen, biology professor at UVic. Reimchen originally formulated these ideas during long-term research on freshwater fish and their predators at a remote lake on Haida Gwaii, an archipelago on the northern coast of British Columbia.

Source: University of Victoria [August 20, 2015]

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The Sumatran rhino is extinct in the wild in Malaysia

Leading scientists and experts in the field of rhino conservation state in a new paper that it is safe to consider the Sumatran rhinoceros extinct in the wild in Malaysia. The survival of the Sumatran rhino now depends on the 100 or fewer remaining individuals in the wild in Indonesia and the nine rhinos in captivity.

Sumatran rhino [Credit: Rasmus Gren Havmoller]

Despite intensive survey efforts, there have been no signs of the wild Sumatran rhinoceros (Dicerorhinus sumatrensis) in Malaysia since 2007, apart from two females that were captured for breeding purposes in 2011 and 2014. Scientists now consider the species extinct in the wild in Malaysia. The experts urge conservation efforts in Indonesia to pick up the pace.

The conclusions are published online in Oryx, the International Journal of Conservation, led by the Center for Macroecology, Evolution and Climate at the University of Copenhagen. Partners include WWF, the International Rhino Foundation and IUCN, the International Union for Conservation of Nature, which is in charge of the global Red List of Threatened Species.

Surviving rhinos are too far apart

"It is vital for the survival of the species that all remaining Sumatran rhinos are viewed as a metapopulation, meaning that all are managed in a single program across national and international borders in order to maximize overall birth rate. This includes the individuals currently held in captivity," says lead author and PhD student Rasmus Gren Havmoller from the Center for Macroecology, Evolution and Climate.

The experts point to the creation of intensive management zones as a solution; areas with increased protection against poaching, where individual rhinos can be relocated to, in order to increase the number of potential and suitable mating partners.

Historically ranging across most of South-east Asia, the Sumatran rhino is now only found in the wild in Indonesia. Here, less than 100 individuals in total are estimated to live in three separate populations, one of which has seen a critical decline in distribution range of 70 % over the last decade. This trend echoes how the Sumatran rhino population dropped from around 500 to extinction between 1980 and 2005 in Sumatra's largest protected area, the enormous 1,379,100 hectare Kerinci Sebelat National Park.

Apart from the wild populations, nine Sumatran rhinos are in captivity, with one in Cincinnati Zoo in U.S.A (soon to be moved to Indonesia), three held at facilities in Sabah, Malaysia for attempts to produce embryos by in vitro fertilization, and five in the Sumatran Rhino Sanctuary in Sumatra, Indonesia.

Two year old conservation strategy awaits political will

The intensive management zones as well as the single population strategy are two of four key actions identified back in April 2013 at the Sumatran Rhino Crisis Summit in Singapore and agreed upon that same year by the Indonesian government in the Bandar Lampung Declaration.

"The tiger in India was saved from extinction due to the direct intervention of Mrs. Gandhi, the then prime minister, who set up Project Tiger. A similar high level intervention by President Joko Widodo of Indonesia could help pull the Sumatran rhinos back from the brink" says Christy Williams, co-author and coordinator of the WWF Asian and Rhino and Elephant Action Strategy.

Widodo Ramono, co-author and Director of the Rhino Foundation of Indonesia (YABI) elaborates: "Serious effort by the government of Indonesia should be put to strengthen rhino protection by creating Intensive Protection Zone (IPZ), intensive survey of the current known habitats, habitat management, captive breeding, and mobilizing national resources and support from related local governments and other stakeholders."

The global conservation strategy also included the continued development of Rhino Protection Units at sites with remaining breeding populations. While this has been achieved, the authors highlight a need for strengthening the units against poaching efforts, especially in northern Sumatra. With a high demand for rhinoceros horns in black markets in Asia, poaching continues to be a significant threat to the species.

Finally, captive breeding was included in 2013 as one of the key conservation actions, but the necessary reproductive technology may still take years to develop, during which time we may lose the Sumatran rhino in the wild, says the authors.

Source: Natural History Museum of Denmark [August 20, 2015]

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The 'End of the high seas,' or we watch the seas die

Even optimistic estimates for what might be achieved at December's Climate Change Conference (COP21) in Paris will not be enough to save the world's coral reefs, according to a Plenary session analysis presented at the Goldschmidt conference in Prague.

The left side of this photo shows a healthy reef at Heron Island. The right side shows
 an example of a degraded reef off Townsville after attack from Crown of Thorns
 and bleaching [Credit: Ove Hoegh-Guldberg/Global Change Institute
 at the University of Queensland]

Speaking to the world's major gathering of geochemists, Professor Peter F Sale (University of Windsor, Canada) spelled out the stark choice facing climate scientists in the run-up to the Paris conference. The stated aim for the COP21 climate conference is to limit a temperature increase to less than +2C by the end of the century.

According to Professor Sale: "Even if Paris is wildly successful, and a treaty is struck, ocean warming and ocean acidification are going to continue beyond the end of this century."

He continued: "This is now serious; I find it very unlikely that coral reefs as I knew them in the mid-1960s will still be found anywhere on this planet by mid-century. Instead, we will have algal-dominated, rubble-strewn, slowly eroding limestone benches. I see little hope for reefs unless we embark on a more aggressive emissions reduction plan. Aiming for CO2 at 350ppm, or a total warming of around 1C is scientifically defendable, and would give reefs a good chance; a number of coral reef scientists have called for this.

A goal of stabilising CO2 at less than 350ppm is also environmentally cautious. Getting to +2 degrees Celsius or so, overshooting along the way, is unwise, self-defeating, and may have far more serious consequences than are dreamed of by politicians happily negotiating minimalist responses to climate change

"As well as CO2 emissions, we must also deal with our other insults to the oceans. We have lost 90% of our commercial fish biomass since the 1940's, we are polluting coastal waters, and the great majority of marine protected areas are not being protected. Either we agree limits, which means the end of the' high seas', or we let large parts of the seas die."

Professor Sale summarised: "Knowing what we are doing, do we have the ethical right to eliminate an entire ecosystem from this planet? It's never been done before. But watching as our actions lead to the loss of all coral reefs on the planet is like removing all rainforests. I don't believe we have that right."

Professor Ove Hoegh-Guldberg, Coordinating Lead Author of section on 'The Ocean' within the latest IPCC (Intergovernmental Panel on Climate Change) report, said: "We need to wake up to the idea that business as usual, even clever taxation schemes, will not act fast enough to reduce global emissions. This is a global emergency, which requires us to decarbonise within the next 20 years, or face temperatures that will eliminate ecosystems like coral reefs, and indeed many systems that humans depend on."

"At the same time, dealing with non-climate stresses will be vitally important -- we must buy time by building resilience in Earth's biological systems, given that even more stringent activities will still result in much warmer and more acidic oceans, than today"

Coral expert, Professor John (Charlie) Veron, former chief scientist of the Australian Institute of Marine Science commented: "The extreme gravity of the current predicament is now widely acknowledged by reef and climate scientists. They also accept that only drastic action starting now will prevent wholesale destruction of reefs and other similarly affected ecosystems. Should humanity not be successful in preventing these threats from becoming reality no amount of management or expenditure will save future generations from the consequences of our failed guardianship."

Source: European Association of Geochemistry [August 17, 2015]

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Substantial glacier ice loss in Central Asia's largest mountain range

Glaciers in Central Asia experience substantial losses in glacier mass and area. Along the Tien Shan, Central Asia's largest mountain range, glaciers have lost 27% of their mass and 18% of their area during the last 50 years. An international research team led by the GFZ German Research Centre for Geosciences and including the institute of the French Centre National de la Recherche Scientifique (CNRS) at Rennes University in particular, estimated that almost 3000 square kilometres of glaciers and an average of 5.4 gigatons of ice per year have been lost since the 1960s. In the current online issue of Nature Geoscience, the authors estimate that about half of Tien Shan's glacier volume could be depleted by the 2050s.

Glaciological field measurements on a glacier in the Jetim-Bel range, Kyrgyzstan. 
Systematic in-situ surveys as pictured are essential for providing ground truth 
data against which satellite observation can be compared 
[Credit: D. Farinotti/GFZ/WSL]

Glaciers play an important role in the water cycle of Central Asia. Snow and glacier melt from the Tien Shan is essential for the water supply of Kazakhstan, Kyrgyzstan, Uzbekistan, and parts of China. "Despite this importance, only little was known about how glaciers in this region changed over the last century" the principal investigator Daniel Farinotti explains. Most of the direct monitoring programs, that were shut down with the collapse of the Soviet Union, are resumed only today, and modern observation techniques often cover a limited time span only.

A lake mirrors some fresh-snow covered glaciers in the Teskey Ala-Too, 
Kyrgyzstan. Yet the appearance is deceiving: Glaciers in the 
Tien Shan are losing mass at a rapid pace 
[Credit: D. Farinotti/GFZ/WSL]

GFZ-researcher Farinotti and colleagues now present a reconstruction of the glacier evolution in the Tien Shan. "We combined various methods based on satellite gravimetry, laser altimetry and glaciological modelling" Farinotti says. "This way, we were able to reconstruct the evolution of every single glacier. Currently, the Tien Shan is losing ice at a pace that is roughly twice the annual water consumption of entire Germany."

Glaciers in Central Asia

Glaciers can store water as glacier ice over decades, and transfer winter precipitation into the summer months by releasing it as melt water. This is particularly important in seasonally arid regions, i.e. regions that have months with virtually no precipitation, since local water supply is then closely linked to meltwater availability.

Two unnamed glaciers in the Terskey range, Kyrgyzstan. The topographic control
 on glacier occurrence is striking: North-facing slopes are glacierized, 
whilst south-facing slopes are completely free of ice
[Credit: D. Farinotti/GFZ/WSL]

Central Asia is the outstanding case for human dependence on water seasonally delayed by glaciers. Nowhere the question about the glacier state is linked so closely to questions of water availability and, thus, food security.

North facing slope of the Jetim-Bel range, Kyrgyzstan. Glacier melt is an essential 
water resource in an otherwise dry environment Two unnamed glaciers in the
 Terskey range, Kyrgyzstan. The topographic control on glacier occurrence
 is striking: North-facing slopes are glacierized, whilst 
south-facing slopes are completely free of ice 
[Credit: D. Farinotti/GFZ/WSL]

The pace of glacier retreat noticeably accelerated between the 1970s and the 1980s. Daniel Farinotti: "The long-term signal is clearly related to the overall rise in temperature." In fact, the study shows that the rise in temperature, and summer temperature in particular, is a primary control for glacier evolution in the region. "For Central Asia, this statement is less trivial than it might seem at first glance: Since the winter months in the region are very dry and the mountains are that high, glaciers receive most of their snowfalls during summer." Farinotti explains. "This means that an increased temperature contributes to both, increased melt and reduced glacier nourishment -- and obviously, both contributes to glacier wastage."

By using the latest climate projections, which anticipate an additional 2 °C warming of summer temperatures in the period 2021 -- 2050, the authors also provide a first outlook for the future evolution: Half of the total glacier ice volume present in the Tien Shan today could be lost by the 2050s.

Source: GFZ GeoForschungsZentrum Potsdam, Helmholtz Centre [August 17, 2015]

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1,800 years of global ocean cooling halted by global warming

Prior to the advent of human-caused global warming in the 19th century, the surface layer of Earth's oceans had undergone 1,800 years of a steady cooling trend, according to a new study. During the latter half of this cooling period, the trend was most likely driven by large and frequent volcanic eruptions.

Compared to the atmosphere, the oceans can absorb much more heat and trap it for
 longer periods of time. Thus the ocean can buffer short-term changes in global
 temperature. But when events such as volcanic eruptions cluster together
 in a relatively short period of time, the temperature changes can 
become prolonged [Credit: Kathryn Hansen/NASA]

An international team of researchers reported these findings in the August 17, 2015 issue of the journal Nature Geoscience. The study also indicates that the coolest temperatures occurred during the Little Ice Age--a period that spanned the 16th through 18th centuries and was known for cooler average temperatures over land.

The concurrence of cooling events on both land and sea suggests that a global cooling phenomenon was erased by subsequent human-caused global warming.

"Today, the Earth is warming about 20 times faster than it cooled during the past 1,800 years," said Michael Evans, second author of the study and an associate professor in the University of Maryland's Department of Geology and Earth System Science Interdisciplinary Center (ESSIC). "This study truly highlights the profound effects we are having on our climate today."

Compared to the atmosphere, the oceans can absorb much more heat and trap it for longer periods of time. Thus the ocean can buffer short-term changes in global temperature. But when events such as volcanic eruptions cluster together in a relatively short period of time, the temperature changes can become prolonged.

"Volcanic eruptions have a short-term cooling effect on the atmosphere, but our results showed that when volcanic eruptions occurred more frequently, there was long-term ocean cooling," said lead author Helen McGregor, an Australian Research Council (ARC) Future Fellow at the University of Wollongong in Australia. "With this research, we now have new insight into the century-scale global sea-surface temperature variations that came before human-made greenhouse gas forcing."

Results of the global sea surface temperature compilation from Ocean2k: A cooling over the past two millenium was reversed only in the most recent two centuries. Fifty-seven previously published and publicly available marine sea surface temperature reconstructions were combined and compiled into 200-year brackets, represented by the boxes. The thin horizontal lines dividing each box are the median of the values in that box. The thick blue line is the median of these values weighted for differences in the region of the global ocean in which they were found. (More in Figure 2a in the paper and Supplementary Table S13). [Credit: Modified version of Fig 2a in McGregor et al. 
Nature Geoscience 2015]

The scientists are the first to combine 57 previously published marine surface temperature reconstructions that cover all of the world's oceans, from near-polar to tropical regions. The team compiled the data within 200-year brackets to observe long-term trends, and then compared the findings to land-based reconstructions, which revealed similar cooling trends.

"No matter how we divided the data set, the cooling trend stands out as a robust signal," McGregor said.

To investigate the cause of the cooling trend, the researchers turned to climate models. They examined how sea-surface temperatures reacted to various "forcing" factors, such as changes in solar output, Earth's orbit, land use, volcanic activity and greenhouse gases. Only volcanic events resulted in a cooling trend that matched the team's real-world observations.

Understanding how forcing factors changed ocean temperatures in the past can open a window into future climate change.

"Model simulations by others have shown us that the oceans can impart a substantial delay in the warming of the surface climate," said Evans, who is also the lead of the Ocean2k working group of the Past Global Changes (PAGES) program. "With much of the heat from global warming entering our oceans, recent ocean surface warming may foreshadow additional future warming, in the same way ocean cooling appeared as a long-term response to large and frequent volcanic events in recent centuries."

"We are still learning how the oceans mediate climate variations," Evans added. "Further work combining both observations and simulations of ocean climate will refine our understanding of the ocean's role in climate change."

Source: University of Maryland [August 17, 2015]

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Chinese cave 'graffiti' tells a 500-year story of climate change and impact on society

An international team of researchers, including scientists from the University of Cambridge, has discovered unique 'graffiti' on the walls of a cave in central China, which describes the effects drought had on the local population over the past 500 years.

An inscription from 1891 found in Dayu Cave. It reads: On May 24th, 17th year 
of the Emperor Guangxu period (June 30th, 1891 CE), Qing Dynasty, the local mayor, 
Huaizong Zhu led more than 200 people into the cave to get water. A fortuneteller
 named Zhenrong Ran prayed for rain during a ceremony [Credit: L. Tan]

The information contained in the inscriptions, combined with detailed chemical analysis of stalagmites in the cave, together paint an intriguing picture of how societies are affected by droughts over time: the first time that it has been possible to conduct an in situ comparison of historical and geological records from the same cave. The results, published in the journal Scientific Reports, also point to potentially greatly reduced rainfall in the region in the near future, underlying the importance of implementing strategies to deal with a world where droughts are more common.

The inscriptions were found on the walls of Dayu Cave in the Qinling Mountains of central China, and describe the impacts of seven drought events between 1520 and 1920. The climate in the area around the cave is dominated by the summer monsoon, in which about 70% of the year's rain falls during a few months, so when the monsoon is late or early, too short or too long, it has a major impact on the region's ecosystem.

"In addition to the obvious impact of droughts, they have also been linked to the downfall of cultures -- when people don't have enough water, hardship is inevitable and conflict arises," said Dr Sebastian Breitenbach of Cambridge's Department of Earth Sciences, one of the paper's co-authors. "In the past decade, records found in caves and lakes have shown a possible link between climate change and the demise of several Chinese dynasties during the last 1800 years, such as the Tang, Yuan and Ming Dynasties."

According to the inscriptions in Dayu Cave, residents would come to the cave both to get water and to pray for rain in times of drought. An inscription from 1891 reads, "On May 24th, 17th year of the Emperor Guangxu period, Qing Dynasty, the local mayor, Huaizong Zhu led more than 200 people into the cave to get water. A fortune-teller named Zhenrong Ran prayed for rain during the ceremony."

Another inscription from 1528 reads, "Drought occurred in the 7th year of the Emperor Jiajing period, Ming Dynasty. Gui Jiang and Sishan Jiang came to Da'an town to acknowledge the Dragon Lake inside in Dayu Cave."

While the inscriptions are business-like in tone, the droughts of the 1890s led to severe starvation and triggered local social instability, which eventually resulted in a fierce conflict between government and civilians in 1900. The drought in 1528 also led to widespread starvation, and there were even reports of cannibalism.

"There are examples of things like human remains, tools and pottery being found in caves, but it's exceptional to find something like these dated inscriptions," said Dr Liangcheng Tan of the Institute of Earth Environment at the Chinese Academy of Sciences in Xi'an, and the paper's lead author. "Combined with the evidence found in the physical formations in the cave, the inscriptions were a crucial way for us to confirm the link between climate and the geochemical record in the cave, and the effect that drought has on a landscape."

The researchers removed sections of cave formations, or speleothems, and analysed the stable isotopes and trace elements contained within. They found that concentrations of certain elements were strongly correlated to periods of drought, which could then be verified by cross-referencing the chemical profile of the cave with the writing on the walls.

When cut open, speleothems such as stalagmites frequently reveal a series of layers that record their annual growth, just like tree rings. Using mass spectrometry, the researchers analysed and dated the ratios of the stable isotopes of oxygen, carbon, as well as concentrations of uranium and other elements. Changes in climate, moisture levels and surrounding vegetation all affect these elements, since the water seeping into the cave is related to the water on the surface. The researchers found that higher oxygen and carbon isotope ratios, in particular, corresponded with lower rainfall levels, and vice versa.

The researchers then used their results to construct a model of future precipitation in the region, starting in 1982. Their model correlated with a drought that occurred in the 1990s and suggests another drought in the late 2030s. The observed droughts also correspond with the El Niño-Southern Oscillation (ENSO) cycle. Due to the likelihood that climate change caused by humans will make ENSO events more severe, the region may be in for more serious droughts in the future.

"Since the Qinling Mountains are the main recharge area of two larger water transfer projects, and the habitat for many endangered species, including the iconic giant panda, it is imperative to explore how the region can adapt to declining rain levels or drought," said Breitenbach. "Things in the world are different from when these cave inscriptions are written, but we're still vulnerable to these events -- especially in the developing world."

Source: University of Cambridge [August 14, 2015]

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Rhino horns, elephant tusks seized in Vietnam

Police in Vietnam have seized more than 700 kilograms (1,500 pounds) of rhino horns and elephant tusks believed to have originated from Mozambique, state media said Friday.

Authorities confiscated the tusks and horns hidden in two containers on the 
King Prian ship when it docked at Tien Sa port [Credit: VOV]

The haul of prized animal parts was discovered hidden in two containers on board a ship carrying ground stones at the central port of Da Nang on Thursday, Tuoi Tre newspaper said.

"The elephant tusks weighed 593 kilograms and the rhino horn chunks weighed 142 kilograms," the report said, adding that the illegal shipment had come via Malaysia.

The final destination of the shipment was not reported but the boat was scheduled to stop in on Vietnam's northern Hai Phong port.

Communist Vietnam has long been accused of being one of the world's worst countries for trade in endangered species.

There have been a number of campaigns to warn Vietnamese not to use products from endangered animals but they have had little success.

Demand for rhino horn remains high with people mistakenly believing it can cure anything from cancer to hangovers despite an absolute dearth of scientific evidence.

Horns are made from keratin, the same substance that makes up finger nails and hair in humans.

Tusks and other body parts of elephants are prized for decoration, as talismans, and for use in traditional medicine.

The rhino horn trade was banned globally by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) in 1977.

But the trade has flourished in recent years, particularly thanks to demand from Vietnam and China with devastating results for Africa's rhino populations.

There are around just 5,000 black rhinos left on the planet and an estimated 20,000 white rhinos, mostly in southern Africa.

In 2011, the western black rhinoceros, a subspecies last seen in Cameroon, was declared extinct.

Source: AFP [August 14, 2015]

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