Jump in number of global swine flu deaths

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The virus was first recorded in Mexico

The global number of swine flu deaths has jumped by more than 1,000 in a week, latest figures from the World Health Organization (WHO) show.

At least 7,826 people are now known to have died following infection with the H1N1 virus since it first emerged in Mexico in April.

Europe saw an 85% increase in the week, with the total number of deaths rising from at least 350 to at least 650.

However, in most cases the virus continues to produce mild symptoms.

If every mutation is reported out there it would be like reporting changes in the weather Keiji Fukuda WHO special adviser on pandemic influenza

An overwhelming majority of patients usually recover, even without medical treatment, within a week.

The biggest rise in deaths was recorded in the Americas, where the death toll rose to 5,360 - a rise of 554 cases in one week.

Health authorities in Norway and France have each recorded two fatalities from a mutated strain of H1N1.

China, Japan, Norway, Ukraine and the US have also recorded cases of people being infected with a mutated strain.

Uncertainty

French health officials confirmed that two patients infected by a mutation that was also recently detected in Norway had died in two different cities in France.

SWINE FLU SYMPTOMS 1. High temperature, tiredness and lowered immunity 2. Headache, runny nose and sneezing 3. Sore throat 4. Shortness of breath 5. Loss of appetite, vomiting and diarrhoea 6. Aching muscles, limb and joint pain Source: NHS Fergus on Flu Q&A: Advice about swine flu

"This mutation could increase the ability of the virus to affect the respiratory tracts and, in particular, the lung tissue," said a statement from the government's Health Surveillance Institute.

The French institute added that, in the case of one of the patients who died, the mutation was accompanied by another mutation known to confer resistance to the main drug being used to treat swine flu, which is sold under the brand name Tamiflu.

It was the first drug-resistant strain found in France among the 1,200 strains experts have analysed here, it said.

Speaking on Thursday, Keiji Fukuda, the WHO's special adviser on pandemic influenza, said that conclusions had still to be drawn about the reported mutations.

"The question is whether these mutations suggest that there is a fundamental change going on in viruses out there - whether there's a turn for the worse in terms of severity," he said.

"The answer right now is that we are not sure."

Dr Fukuda noted that mutations were common in influenza viruses.

"If every mutation is reported out there it would be like reporting changes in the weather," he said.

"What we're trying to do when we see reports of mutations is to identify if these mutations are leading to any kinds of changes in the clinical picture - do they cause more severe or less severe disease?

"Also we're trying to see if these viruses are increasing out there as that would suggest a change in epidemiology."

In his latest survey of swine flu developments, the WHO notes that many countries have stopped counting individual cases of swine flu, particularly of milder illness, and the case count is likely to be significantly lower than the actual number of cases that have occurred.

Cell discovery clues to body clock and beating jet lag

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By Dave Lee Health Check, BBC World Service

The discovery could hold the key to solving body clock mysteries

New discoveries into how the body clock works could provide clues to help combat jet lag, research suggests.

A University of Manchester team studied special cells which they say play an important role in regulating a person's body clock.

The cells had been thought to be inactive during the day - but their research found the opposite is true.

It is hoped the findings may also pave the way to combating sleep disorders triggered by body clock malfunctions.

Professor Hugh Piggins, an expert in neuroscience at the university, said the research will allow a new approach to being able to tune our daily clock.

Two cells

The Manchester research turns on its head the idea that the brain keeps the body clock on track by firing more cells during daylight and very few during the night.

There's a lot of interest in the pharmaceutical industry, obviously, to try to develop chemical treatments to reset your daily clock Professor Hugh Piggins

"The traditional model said the clock and the brain communicated to the rest of the brain via the number of electrical impulses that the brain cells were producing," Prof Piggins told the BBC World Service's Health Check programme.

"These impulses would travel around the brain, telling it what time of day it is.

"What we've found is in fact that there are at least two types of cells in this part of the brain."

These brain cells behave unlike any other cell seen so far, and contain a key gene - per1 - which allows them to sustain unusually high levels of "excitability".

The cells becoming so "excited" that they seem quiet or even dead; but then later they calm down, recover and become normally active again.

It is this activity which tells the human body when to be awake.

Sleep dysfunction

HEALTH CHECK Health Check is the weekly health programme broadcast from the BBC World Service It is broadcast on Monday at 1032GMT and repeated at 1532GMT, 2032GMT and on Tuesday at 0132GMT It is also available as a podcast

Prof Piggins added: "There's a lot of interest in the pharmaceutical industry, obviously, to try to develop chemical treatments to reset your daily clock to help counteract things like jetlag.

"Or, perhaps more importantly, different kind of sleep disorders for which dysfunctions in this clock are often involved."

This study marks the first time these "quiet" cells have been studied.

"This may mean that elsewhere in the brain there are cells like this that can also survive these very unusual conditions."

Climate change around the world

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World leaders at the G8 summit in Italy are negotiating a deal to limit the effects of climate change. Click on the buttons and words above to find out more about the impact of global warming.

AFRICA

Some regions are likely to experience water shortages. Coupled with increasing demand, this is likely to result in large increases in the number of people at risk of water scarcity. It is likely to affect livelihoods, the report by the International Panel on Climate Change says.

Projected reductions in the area suitable for growing crops, and in the length of the growing season, are likely to produce an increased risk of hunger. In some countries, yields from rain-fed agriculture could be reduced by up to 50% by 2020.

Rising sea levels threaten large cities. Degradation of coral reefs and mangroves is likely, with impacts on local fisheries and tourism.

Rising temperatures, coupled with over-fishing, will decrease the supply of fish from large lakes, with important impacts on food supplies.

ASIA

Glacier melting in the Himalayas is virtually certain to disrupt water supplies within the next 20 to 30 years. Floods and rock avalanches are virtually certain to increase. Heavily-populated coastal regions, including the deltas of rivers such as the Ganges and Mekong, are likely to be at risk of increased flooding.

Economic development is likely to be impacted by the combination of climatic change, urbanisation, and rapid economic and population growth.

Forecast changes in temperature and rainfall are likely to reduce crop yields overall, increasing the risk of hunger.

The presence of lethal diarrhoeal diseases associated with floods and droughts is expected to rise in East, South and Southeast Asia and rises in coastal water temperature could exacerbate cholera in South Asia.

AUSTRALIA AND NEW ZEALAND

Ongoing water shortages, notably in southern and eastern Australia, are likely to get worse by 2030.

Ecologically important regions such as the Great Barrier Reef and Kakadu National Park are likely to lose a significant part of their wildlife before then, by 2020.

Some coastal communities are very likely to see an increased risk of coastal storms and flooding.

Temperature rises of 1C-2C are likely to bring benefits to cooler areas, such as New Zealand, in the form of longer growing seasons and reduced energy demand. Greater warming is likely to bring a net negative impact - such as increased risk of drought and fire.

EUROPE

Nearly all European regions are expected to be negatively affected by some future impacts of climate change.

Central and Eastern European countries could face less summer rainfall, causing higher water stress. Health risks due to heat waves are expected to increase. Forest productivity is expected to fall and the frequency of peatland fires to increase.

Southern European countries are very likely to see reduced water supplies, lower crop production, more wildfires and health impacts from increased heatwaves.

Northern countries are likely to benefit from increased crop yields, forest productivity, and food supplies from the North Atlantic. By 2020, most areas of Europe are likely to see an increased flood risk.

LATIN AMERICA

Increasing temperatures and decreases in soil water in the eastern Amazon region would lead to replacement of tropical forest by savannah. Species extinctions are likely.

Drier areas are likely to see salinisation and desertification of agricultural land, with falling crop yields and livestock productivity reducing food security. However, soybean yields are likely to increase in temperate zones.

Sea level rise is very likely to bring flooding to low-lying regions such as the coast of El Salvador, Guyana and the Rio de la Plata estuary. Increasing sea temperatures are likely to impact coral reefs and south-east Pacific fish stocks.

Changes in rainfall patterns and the disappearance of glaciers are projected to significantly affect water availability for human consumption, agriculture and energy generation.

NORTH AMERICA

Warming in western mountains is very likely to reduce snowpack, bringing more floods in winter and reduced water supplies in summer.

Increases in problems with pests, diseases and forest fires are likely.

Cities with a history of heat waves are likely to experience many more, with potential health impacts, especially for the elderly.

Rising sea levels, severe weather and storm surges, combined with population growth in coastal areas, are very likely to increase economic losses.

POLAR REGIONS: ARCTIC AND ANTARCTICA

Reductions are likely in the thickness and extent of glaciers and ice sheets, and the extent of sea ice and permafrost.

The depth of summer permafrost melting is likely to increase.

Changes to natural ecosystems are likely to impact migrating birds, mammals and higher predators adversely. Specific ecosystems and habitats are expected to be vulnerable, as climatic barriers to species invasions are lowered.

There are virtually certain to be both negative and positive effects on Arctic peoples. Detrimental impacts would include those on infrastructure and traditional indigenous ways of life while beneficial effects would include reduced heating costs and more navigable northern sea routes.

SMALL ISLANDS

Sea level rise is likely to worsen floods, storm surges and coastal erosion, with impacts on the socio-economic wellbeing of island communities.

Beach erosion and coral bleaching are likely to reduce tourism.

There is strong evidence that water resources in small islands are likely to be seriously compromised.

Increased invasion by non-native species is likely.

WATER

The supply of water is very likely to increase at higher latitudes and in some wet tropics, including populous areas in east and southeast Asia. It is very likely to decrease over much of the mid-latitudes and dry tropics, which are presently water-stressed areas.

Drought-affected areas will likely increase. Instances of extreme rainfall are likely to increase in frequency and intensity, raising the risk of floods. Increases in the frequency and severity of floods and droughts will have implications on sustainable development.

Water volumes stored in glaciers and snow cover are very likely to decline, reducing summer and autumn flows in regions where more than one sixth of the world population currently live.

ECOSYSTEMS

Many ecosystems are likely to be challenged beyond their capacity to adapt over the course of the century by an unprecedented combination of climate change, associated disturbances such as wildfires, and other aspects of modern-day global change.

In the second half of this century, ecosystems on land are likely to become a net source of carbon rather than a net absorber. This extra carbon will amplify climate change.

Roughly 20-30% of species are likely to be at high risk of irreversible extinction if the global average temperature rises by 1.5-2.5C beyond 1990 levels. For increases in global average temperature exceeding 1.5-2.5C, there are very likely to be major changes in ecosystems which will adversely effect the environmental goods and services which humans use.

FOOD

Crop yields are likely to increase at higher latitudes for global average temperature increases of up to 1-3C (depending on the crop), and then decrease beyond that. This is even after allowing for effects of CO2 fertilisation.

At lower latitudes, especially the seasonally dry tropics, crop yield potential is likely to decrease for even small global temperature increases, which would increase risk of hunger.

Global agricultural production potential is likely to increase with increases in global average temperature up to about 3C, but above this it is very likely to decrease.

Increased frequency of droughts and floods would affect local production negatively, especially in subsistence sectors at low latitudes.

COASTS

Coasts are very likely to be exposed to increasing risks due to climate change and sea level rise, and the effect will be exacerbated by increasing human-induced pressures on coastal areas.

It is likely that corals will experience a major decline due to increased bleaching and mortality due to rising seawater temperatures. Salt marshes and mangroves will also be negatively affected by sea-level rise.

Many millions more people are expected to be flooded every year due to sea-level rise by the 2080s, especially in densely populated and low-lying settlements which already face other challenges such as tropical storms or local coastal subsidence. The numbers affected will be largest in the mega-deltas of Asia, but small islands face the highest relative increase in risk.

INDUSTRY

The benefits and costs of climate change for industry, settlement, and society will vary widely by location and scale. Some of the effects in temperate and polar regions will be positive, and others elsewhere will be negative. Generally, a higher degree of warming is more likely to bring negative consequences.

The most vulnerable industries, settlements and societies are those in coastal and river flood plains, those whose economies are closely linked with climate-sensitive resources, and those in areas prone to extreme weather events, especially where rapid urbanisation is occurring.

Poor communities can be especially vulnerable because they tend to be concentrated in relatively high-risk areas, have more limited coping capacities, and can be more dependent on climate-sensitive resources such as local water and food supplies. Where extreme weather events become more intense, the economic costs of those events will increase, and these increases are likely to be substantial in the areas most directly affected.

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HEALTH

Projected climate change is likely to affect millions of people, particularly those with low capacity to adapt, through increases in malnutrition and consequent disorders.

This will have implications for child growth and development; increased deaths, disease and injury due to heat waves, floods, storms, fires and droughts, the altered burden of water-related diseases; the increased frequency of cardio-respiratory diseases due to higher concentrations of ground level ozone, and the movement of some infectious disease carriers into new regions. vectors.

Climate change is likely to have some mixed effects, such as the expansion and contraction of the range of malaria in different regions. In some places, climate change is likely to bring some benefits to health such as fewer deaths from cold exposure.

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IPCC definitions of probability of occurrence

Virtually certain: more than 99%
Extremely likely: more than 95%
Very likely: more than 90%
Likely: more than 66%
More likely than not: more than 50%
Very unlikely: less than 10%
Extremely unlikely: less than 5%

Copenhagen: What's your solution?

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If you had the microphone at the Copenhagen climate summit, what would you say?

What is your message to world leaders on global warming?

BBC News would like you to send us your message for Copenhagen.

The best video messages we receive will be featured in a special televised debate on BBC News, at the climax of the conference.

Last chance

The UN Climate Change Conference begins in Copenhagen, Denmark, on December 7.

Example of a video message - Children send their messages to Barack Obama

Some say it is our last chance to save the world from runaway climate change.

Many hope that world leaders will agree significant cuts in greenhouse gas emissions; and compensation for countries suffering from global warming.

But talks so far have been slow, with key nations cagey to commit. There are fears that no firm action will be agreed.

• Are you worried about climate change?

• What deal would you strike in Copenhagen?

• Who should cut their emissions? By how much? And how should they make these cuts?

• How would you improve the negotiation process?

Send us your comments in video

Life in 2050

How will climate change affect you in future?

Is it already affecting you now?

Perhaps you are farmer whose crops are vulnerable.

Or you may live in a coastal area at risk of flooding.

You may be an oil worker, or a coal miner whose job is threatened.

Whatever you do, we'd like to hear from you.

Tell us:

• Why does climate change matter to you?

• How much are you personally willing to adapt, to live more sustainably?

• Are you prepared to change the way you travel, the food you eat, or to have fewer children?

• Would you pay more taxes - to invest in green energy and compensate countries hurt by climate change?

A brief history of climate change

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As the UN climate summit in Copenhagen approaches, BBC News environment correspondent Richard Black traces key milestones, scientific discoveries, technical innovations and political action.

The Newcomen Engine foreshadowed industrial scale use of coal

1712 - British ironmonger Thomas Newcomen invents the first widely used steam engine, paving the way for the Industrial Revolution and industrial scale use of coal.

1800 - world population reaches one billion.

1824 - French physicist Joseph Fourier describes the Earth's natural "greenhouse effect". He writes: "The temperature [of the Earth] can be augmented by the interposition of the atmosphere, because heat in the state of light finds less resistance in penetrating the air, than in re-passing into the air when converted into non-luminous heat."

1861 - Irish physicist John Tyndall shows that water vapour and certain other gases create the greenhouse effect. "This aqueous vapour is a blanket more necessary to the vegetable life of England than clothing is to man," he concludes. More than a century later, he is honoured by having a prominent UK climate research organisation - the Tyndall Centre - named after him.

1886 - Karl Benz unveils the Motorwagen, often regarded as the first true automobile.

1896 - Swedish chemist Svante Arrhenius concludes that industrial-age coal burning will enhance the natural greenhouse effect. He suggests this might be beneficial for future generations. His conclusions on the likely size of the "man-made greenhouse" are in the same ballpark - a few degrees Celsius for a doubling of CO2 - as modern-day climate models.

Svante Arrhenius unlocked the man-made greenhouse a century ago

1900 - another Swede, Knut Angstrom, discovers that even at the tiny concentrations found in the atmosphere, CO2 strongly absorbs parts of the infrared spectrum. Although he does not realise the significance, Angstrom has shown that a trace gas can produce greenhouse warming.

1927 - carbon emissions from fossil fuel burning and industry reach one billion tonnes per year.

1930 - human population reaches two billion.

1938 - using records from 147 weather stations around the world, British engineer Guy Callendar shows that temperatures had risen over the previous century. He also shows that CO2 concentrations had increased over the same period, and suggests this caused the warming. The "Callendar effect" is widely dismissed by meteorologists.

1955 - using a new generation of equipment including early computers, US researcher Gilbert Plass analyses in detail the infrared absorption of various gases. He concludes that doubling CO2 concentrations would increase temperatures by 3-4C.

1957 - US oceanographer Roger Revelle and chemist Hans Suess show that seawater will not absorb all the additional CO2 entering the atmosphere, as many had assumed. Revelle writes: "Human beings are now carrying out a large scale geophysical experiment..."

1958 - using equipment he had developed himself, Charles David (Dave) Keeling begins systematic measurements of atmospheric CO2 at Mauna Loa in Hawaii and in Antarctica. Within four years, the project - which continues today - provides the first unequivocal proof that CO2 concentrations are rising.

Change in future is likely to be more fundamental and more widespread than anything we have known hitherto Margaret Thatcher

1960 - human population reaches three billion.

1965 - a US President's Advisory Committee panel warns that the greenhouse effect is a matter of "real concern".

1972 - first UN environment conference, in Stockholm. Climate change hardly registers on the agenda, which centres on issues such as chemical pollution, atomic bomb testing and whaling. The United Nations Environment Programme (Unep) is formed as a result.

1975 - human population reaches four billion.

1975 - US scientist Wallace Broecker puts the term "global warming" into the public domain in the title of a scientific paper.

1987 - human population reaches five billion

1987 - Montreal Protocol agreed, restricting chemicals that damage the ozone layer. Although not established with climate change in mind, it has had a greater impact on greenhouse gas emissions than the Kyoto Protocol.

1988 - Intergovernmental Panel on Climate Change (IPCC) formed to collate and assess evidence on climate change.

1989 - UK Prime Minister Margaret Thatcher - possessor of a chemistry degree - warns in a speech to the UN that "We are seeing a vast increase in the amount of carbon dioxide reaching the atmosphere... The result is that change in future is likely to be more fundamental and more widespread than anything we have known hitherto." She calls for a global treaty on climate change.

1989 - carbon emissions from fossil fuel burning and industry reach six billion tonnes per year.

The CO2 concentration, as measured at Mauna Loa, has risen steadily

1990 - IPCC produces First Assessment Report. It concludes that temperatures have risen by 0.3-0.6C over the last century, that humanity's emissions are adding to the atmosphere's natural complement of greenhouse gases, and that the addition would be expected to result in warming.

1992 - at the Earth Summit in Rio de Janeiro, governments agree the United Framework Convention on Climate Change. Its key objective is "stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system". Developed countries agree to return their emissions to 1990 levels.

1995 - IPCC Second Assessment Report concludes that the balance of evidence suggests "a discernible human influence" on the Earth's climate. This has been called the first definitive statement that humans are responsible for climate change.

1997 - Kyoto Protocol agreed. Developed nations pledge to reduce emissions by an average of 5% by the period 2008-2012, with wide variations on targets for individual countries. US Senate immediately declares it will not ratify the treaty.

1998 - strong El Nino conditions combine with global warming to produce the warmest year on record. The average global temperature reached 0.52C above the mean for the period 1961-1990 (a commonly-used baseline).

1998 - publication of the controversial "hockey stick" graph indicating that modern-day temperature rise in the northern hemisphere is unusual compared with the last 1,000 years. The work would later be the subject of two enquiries instigated by the US Congress.

Rajendra Pachauri's IPCC netted the Nobel Peace Prize in 2007

1999 - human population reaches six billion.

2001 - President George W Bush removes the US from the Kyoto process.

2001 - IPCC Third Assessment Report finds "new and stronger evidence" that humanity's emissions of greenhouse gases are the main cause of the warming seen in the second half of the 20th Century.

2005 - the Kyoto Protocol becomes international law for those countries still inside it.

2005 - UK Prime Minister Tony Blair selects climate change as a priority for his terms as chair of the G8 and president of the EU.

2006 - the Stern Review concludes that climate change could damage global GDP by up to 20% if left unchecked - but curbing it would cost about 1% of global GDP.

2006 - carbon emissions from fossil fuel burning and industry reach eight billion tonnes per year.

2007 - the IPCC's Fourth Assessment Report concludes it is more than 90% likely that humanity's emissions of greenhouse gases are responsible for modern-day climate change.

2007 - the IPCC and former US vice-president Al Gore receive the Nobel Peace Prize "for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change".

2007 - at UN negotiations in Bali, governments agree the two-year "Bali roadmap" aimed at hammering out a new global treaty by the end of 2009.

2008 - half a century after beginning observations at Mauna Loa, the Keeling project shows that CO2 concentrations have risen from 315 parts per million (ppm) in 1958 to 380ppm in 2008.

2008 - two months before taking office, incoming US president Barack Obama pledges to "engage vigorously" with the rest of the world on climate change.

2009 - China overtakes the US as the world's biggest greenhouse gas emitter - although the US remains well ahead on a per-capita basis.

2009 - 192 governments convene for the UN climate summit in Copenhagen.

Q&A: The Copenhagen climate summit

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In December, delegations from 192 countries will hold two weeks of talks in Copenhagen aimed at establishing a new global treaty on climate change. Here, BBC environment correspondent Richard Black looks at what the talks are about and what they are supposed to achieve.

Why are the Copenhagen talks happening?

The majority of the world's governments believe that climate change poses a threat to human society and to the natural world.

Successive scientific reports, notably those from the Intergovernmental Panel on Climate Change (IPCC), have come to ever firmer conclusions about humankind's influence on the modern-day climate, and about the impacts of rising temperatures.

Two years ago, at the UN climate talks held in Bali, governments agreed to start work on a new global agreement.

The Copenhagen talks mark the end of that two-year period.

Governments hope to leave the Danish capital having completed the new deal.

The talks are technically known as the 15th Conference of the Parties to the United Nations Framework Convention on Climate Change (UNFCCC) - often abbreviated to COP15.

Why is climate change happening - and is it the same as global warming?

The Earth's climate has always changed naturally over time.

For example, variability in our planet's orbit alters its distance from the Sun, which has given rise to major Ice Ages and intervening warmer periods.

According to the last IPCC report, it is more than 90% probable that humankind is largely responsible for modern-day climate change.

A brief history of climate change What's your Copenhagen solution?

The principal cause is burning fossil fuels - coal, oil and gas.

This produces carbon dioxide (CO2), which - added to the CO2 present naturally in the Earth's atmosphere - acts as a kind of blanket, trapping more of the Sun's energy and warming the Earth's surface.

Deforestation and processes that release other greenhouse gases such as methane also contribute.

Although the initial impact is a rise in average temperatures around the world - "global warming" - this also produces changes in rainfall patterns, rising sea levels, changes to the difference in temperatures between night and day, and so on.

This more complex set of disturbances has acquired the label "climate change" - sometimes more accurately called "anthropogenic (human-made) climate change".

Why is a new treaty needed?

The Copenhagen talks sit within the framework of the UNFCCC, established at the Rio de Janeiro Earth Summit in 1992.

In 1997, the UNFCCC spawned the Kyoto Protocol.

Denmark's Environment Minister Connie Hedegaard will chair COP15

But neither of these agreements can curb the growth in greenhouse gas emissions sufficiently to avoid the climate impacts projected by the IPCC.

In particular, the Kyoto Protocol's targets for reducing emissions apply only to a small set of countries and expire in 2012.

Governments want a new treaty that is bigger, bolder, wider-ranging and more sophisticated than the Kyoto agreement.

In June, the G8 and a number of large developing countries agreed that the average temperature rise since pre-industrial times should be limited to 2C (3.6F).

In principle, they are looking to the Copenhagen treaty to curb the growth in greenhouse gas emissions enough to keep the world within that limit.

Who is looking for what in the new treaty?

A lot of issues are involved.

Industrialised nations will set targets for reducing their greenhouse gas emissions in order to mitigate climate change.

The key date for these commitments is 2020, although some countries are looking beyond that, to 2050.

Australia, the EU, Japan and New Zealand have already said what they are prepared to do by 2020.

Richer developing countries are also likely to be asked to constrain their emissions.

If they do make any pledges, they are likely to restrain the growth of emissions rather than making actual cuts.

CLIMATE CHANGE GLOSSARY Select a term from the dropdown: Suggest additions Glossary in full Their commitments are likely to be expressed in terms of a reduction in emissions growth of a certain percentage compared with "business as usual". In order to help developing countries constrain their greenhouse gas emissions, industrialised nations have agreed in principle to help them in areas such as renewable energy. Developing countries are looking for mechanisms that can speed up this technology transfer. Many countries are thinking about how to prepare for the impacts of climate change - what sorts of adaptation will be necessary. These include measures such as building sea defences, securing fresh water supplies and developing new crop varieties. Developing countries are looking for substantial and reliable finance to help them adapt. Their argument is that as the industrialised world has caused the problem, it must pay to sort it out. Measures to protect forests will be a component of the deal. How much will it cost? In general, fossil fuels provide us with our cheapest sources of energy. The main route to reducing greenhouse gas emissions is to avoid burning fossil fuels; so a successful treaty would almost certainly make energy more expensive. Funding clean technologies will be part of any deal There are different analyses of how much it would cost to make this transition quickly enough to avert "dangerous" climate change. Developing countries are looking for money in the order of hundreds of billions of dollars each year for mitigation - the ballpark figure that the International Energy Agency calculates is necessary to fund a large-scale switch to low-carbon energy. A number of studies, including one by the World Bank, also suggest that a further $100bn per year or thereabouts will be needed to help poorer countries adapt. By comparison, the amount of overseas aid currently given each year by rich countries is in the region of $100bn. What are the prospects for a deal? Four broad outcomes are possible from the Copenhagen summit: a comprehensive deal with all loose ends tied up a deal agreeing the "big picture", but with lots of details remaining to be thrashed out over the coming months or years adjournment of the COP, probably until midway through 2010 breakdown. Almost every government attending the talks says it wants a deal; and many contend it is necessary to have the essential ingredients in place by the time the Kyoto Protocol's current targets expire in 2012. But in the weeks leading up to Copenhagen, it has become clear that a full, legally-binding treaty is not possible, with a number of key players suggesting something less ambitious is indicated given the immense amount of detail remaining to be worked out and the fact that the US is not in a position to make firm pledges on mitigating its own emissions or on providing financial support to the developing world. A political agreement appears more likely, with attempts to secure a legally-binding treaty deferred until some point in 2010. Would a Copenhagen deal solve climate change? The global average temperature has already risen by about 0.7C since pre-industrial times. In some parts of the world this is already having impacts - and a Copenhagen deal could not stop those impacts, although it could provide funding to help deal with some of the consequences. Greenhouse gases such as CO2 stay in the atmosphere for decades; and concentrations are already high enough that further warming is almost inevitable. Many analyses suggest an average rise of 1.5C since pre-industrial times is guaranteed. A strong Copenhagen deal might keep the temperature rise under 2C; but given uncertainties in how the atmosphere and oceans respond to rising concentrations of greenhouse gases, it might not. This is why developing countries put such an emphasis on adaptation, which they argue is necessary already. IPCC figures suggest that to have a reasonable chance of avoiding 2C, global emissions would need to peak and start to decline within about 15-20 years. Currently, the cuts pledged by industrialised nations are not enough to halt the overall global rise in emissions. Whatever happens in Copenhagen, further meetings will almost certainly be necessary to finalise the "rules" of any new treaty. Further ahead, at some point governments will almost certainly begin the process of securing the deal after Copenhagen.

Nuclear fuel cycle

http://news.bbc.co.uk Introduction :: Mining uranium Uranium is the basic raw material of both civilian and military nuclear programmes. It is extracted from either open-cast pits or by underground mining. Although uranium occurs naturally all over the world, only a small fraction is found in concentrated ores. When certain atoms of uranium are split in a chain reaction, energy is released. This process is called nuclear fission. In a nuclear power station this fission occurs slowly, while in a nuclear weapon, very rapidly. In both instances, fission must be very carefully controlled. Nuclear fission works best if isotopes - atoms with the same number of protons, but different numbers of neutrons - of uranium 235 (or plutonium 239) are used.These isotopes have almost identical chemical properties, but different nuclear properties. Uranium-235 is known as a "fissile isotope" because of its propensity to split in a chain reaction, releasing energy in the form of heat. When a U-235 atom splits, it emits two or three neutrons. When other U-235 atoms are present, these neutrons collide with them causing the other atoms to split, producing more neutrons. A nuclear reaction will only take place if there are enough u-235 atoms present to allow this process to continue as a self-sustaining chain reaction. This requirement is known as "critical mass". However, every 1,000 atoms of naturally-occurring uranium contain only seven atoms of U-235, with the remaining 993 being denser U-238.