There is no doubt that our planet is warming. Many climatologists have spoken out about the dangers of our continued path on this warming. The reason is there is now a very clear pattern in the scientific evidence documenting that the warming is due largely to human activity. This warming is already causing important changes in the climate. As many phenomena are accelerating, rapid and potentially catastrophic changes in the near future is possible. Further more, it should be realized that this pattern emerges not, as so often suggested, simply from computer simulations, but from the weight and balance of the empirical evidence as well.

In this paper, we shall concentrate on one set of data – ice core records of climatic and environmental variations from the polar regions and low latitude high elevation ice fields in 16 countries. The ongoing widespread melting of high elevation glaciers and ice caps, particularly in the middle and low latitudes, provides some of the strongest evidence to date that a large scale, pervasive, and in some cases rapid changes in Earth’s climate system is underway. This paper highlights observations of 20th and 21st century glacier shrinkage in the Andes, the Himalayas, and on Mount Kilimanjaro. Ice cores retrieved from shrinking glaciers around the world give environmental data for periods ranging from hundreds of years to multiple thousands of years, and they suggest climatological conditions that dominate those regions today are different from those under which these ice fields originally accumulated and have been sustained. The current warming is therefore unusual when viewed from the long term perspective. As well as that we have the 160-year record of direct temperature measurements. Despite all this evidence, plus the well-documented continual increase in atmospheric greenhouse gas concentrations, societies have taken little action to address this global-scale problem. We end here by pointing out what options are open to us: mitigation, adaptation, and suffering.

The Evidence

Glaciers serve as early indicators of climate change. Here we report 35 years of research on ice
core data.

A. Northern hemisphere temperature for last 1000 years

From a variety of high resolution climate recorders such as glacier lengths, tree rings, sediment cores and historical records, it has been found that for most of this period the average temperature has been relatively stable until the 20th century. However, since the industrial revolution, there has been warming, in particular in the last decade so that now there is an average rise of 0.7 deg C from 1900. The temperature rise is most marked in the Arctic, Antarctic and in the interior of large continents.

B. Retreat of mountain glaciers

The world’s mountain glaciers and the ice caps contain less than 4% of the world’s ice cover. But they provide invaluable information about changes in climate. Because glaciers are smaller and thinner than the polar ice sheets, their ratio of surface to volume is greater. So they respond quickly to temperature changes. In particular, warming trends are amplified at higher altitudes where the glaciers are. All glaciers are retreating. They form an ‘early warning system’ for climate change. Here are some notable examples.

• By using a combination of terrestrial maps, satellite images, we have found that the the glaciers on Mount Kilimanjaro have retreated from 1912, 1970, 2000, and 2006. From 1912 to 2006, 85% of ice has disappeared. Figure 1.
• Furtwangler glacier on Kibo, the highest crater on Kilimanjaro has decreased in size and thickness and has divided into two. Figure 2.
• The Quelccaya ice cap, which is located in the southern Peru adjacent to the Amazon basin, is the largest tropical ice field on Earth. Ice has been melting to form lakes and since 1978. 25% of this ice cap has disappeared.
• Himalayan mountains contain more than 15,000 glaciers. Glaciologists at the Institute of Tibetan Plateau Research in Beijing have been monitoring 612 glaciers across the High Asian region since 1980. They have found that from 1980 to 1990, 90% of these glaciers were retreating and from 1990 to 2005, the proportion of retreating glaciers increased to 95%.
• Almost 99% of glaciers in Alaska, Glacial national Park and the Alps are thinning.

C. Loss of polar ice

• Satellite documentation of the area covered by sea ice in the Arctic Ocean is measured every September. This decreased at a rate at a rate of ~8.6 % per decade from 1979 to 2007. In 2007 alone, 24% of the ice disappeared. In 2006, the Northwest Passage was ice free for the first time in recorded history.
• Polar ice sheets respond to temperature rise slower than mountain glaciers. But they are melting too. The Greenland ice sheet has shown a increase in the size and number of lakes in the southern part of the ice sheet. there are many crevices which serve as pipes – moulins which transport water quickly to the bottom of the ice sheet serving as lubricant to speed the flow of the flow of ice into the sea. Recently a large chunk of ice island broke off the Petermann glacier. This event alone does not prove global climate change. But it is the fact that it is part of a long term trend of increasing rates of ice loss, coupled with the fact that temperature is increasing in this region at the rate of 2 deg C per decade that indicates that larger scale global climate change is underway.
• In the Antarctic, it has long ago been predicted that increase in CO2 can result in the break up of the ice sheets. Mean temperature on the Antarctic Peninsula has risen by 2.5 deg C in the last 50 years. Just as an ice cube does not raise the water level in a glass when it melts, so a melting ice sheet leave sea levels unchanged. However, ice sheets buttress the glaciers on land and when these ice sheets collapse, it speed the flow of glaciers into the ocean and cause sea level to rise quickly.
• The loss of ice in the Arctic and Antarctic regions is especially troubling because these are the locations of the largest ice sheets in the world. Of the land ice on the planet, 96% is found on Greenland and Antarctica. Should they all melt, sea level would rise 64 meters. In addition to the rise due to thermal expansion. Although research shows some variability in the rate of ice loss. It is clear that mountain glaciers and polar ice sheets are melting fast and there is no explanation other than global warming. Add to this the laboratory evidence and meteorological measurements, the case for global warming cannot be denied. So what causes global warming?

Causes of Global Warming

Climatologists analyze climate in terms of climate forcing. A climate forcing is an imposed perturbation of the Earth’s energy balance. if the sun shines brighter, that is a positive forcing that warms the Earth. Aerosols reflect sunlight so cause a negative forcing. Climatologists classify 2 classes of forcing: Natural forcing which have existed for millions of years and anthropogenic forcing which are more recent processes caused by human activity

A. Natural Forcings

• The most powerful natural forcing is variation in the orbit of the Earth around the sun. These forcings are partly responsible for both the ice ages (the glacial period during which large regions at high and middle latitudes are covered by thick ice sheets) and for the warm interglacial periods such as the present Holocene epoch which began 10,000 years ago.
• The Earth’s orbit round the sun which gives us seasons.
• Volcanic aerosols like the Mount Pinatubo eruption produce millions of tons of sulfuric gases and ash particles high into the atmosphere blocking sunlight. This lowers the Earth’s temperature for a few years and is a negative forcing.
• Linked oceanic and atmospheric system known as El Nino (ENSO) which occurs every 3 to 7 years in the tropical Pacific and brings warm wet weather to some regions and cool dry weather to other areas.
• Periodic modulations in energy from the sun. These include the 11 to 12 year sunspot cycle. These changes in solar energy could affect atmospheric temperature across large regions for hundreds of years and may have caused the ‘medieval climate anomaly’ that lasted from 1100 AD to 1300 AD, and the ‘little ice age’ during 16th to 19th centuries. However, even though the warming affected certain regions, it does not affect the planet as a whole.

B. Anthropogenic Forcings

There is consensus among climatologists that warming trend we have been experiencing for the past 100 years cannot be accounted for by any of the known natural forcing. Furthermore, it should be emphasized that the rate at which the Earth’s temperature has been rising – the hottest decade on record, is abnormal. Sunspot cycles, for example, can increase the sun’s output, raising temperature in our atmosphere. But we are seeing a temperature increase in the troposphere, the lower level of our atmosphere, and a temperature decrease in the stratosphere, the upper level. This is the exact opposite of what we would get if increased solar energy were responsible. Similarly, global temperatures have increased more at night than during the day, again the opposite of what would occur if the sun were driving global warming. High latitudes have warmed more than low latitudes, and because we get more radiation from the sun at low latitudes we again expect the opposite if the sun were driving those changes. The conclusion is that changes in solar output cannot account for the current period of global warming, ENSO and other natural forcing also fail to explain the steady rapid rise in the earth’s temperature. In particular, this rise in the earth’s temperature is accelerating. This can only be due to anthropogenic human forces.

Animals and plants respiration convert oxygen into CO2. There is naturally a steady amount of greenhouse gas in the atmosphere. (See figures 3 and 4). As the orbital forcing brought the last ice age to an end and gave us the warm Holocene period the last 10,000 years, the oceans warmed releasing CO2 into atmosphere. This trapped infrared energy reflected from the Earth’s surface. This warms the planet. This is a natural and self regulating process. Essential process for life on the planet. But we humans can also change the level of CO2. This is what we are doing! Change the level of greenhouse gases in the atmosphere and the planet heats up or cool down.

When one drills down an ice sheet, the deeper one goes the further back in time. Air bubbles are trapped in ice and by analyzing the composition of these bubbles, one can obtain a history of such as the amount of greenhouse gases, the ratio of oxygen isotopes. One can derive the temperature and other environmental parameters of that time. Figure 3 shows the CO2 ppmv from ice core data for the last 400,000 years Figure 4 shows the carbon dioxide(CO2) and methane(CH4) concentration for the last 800,000 years (over8 glacial cycles) from East Antarctic ice cores Note the extremely high values for today. Since the onset of industrial revolution and our use of fossil fuel, the greenhouse gases began to rise sharply. This sharp rise in the last 2 decades is quite unprecedented. The CO2 concentration is now at 391 pppm (parts per million by volume). A level not seen at any time in the 800,000 years. Methane raises temperature even more than CO2 and the amount of methane in the atmosphere is also at a level not seen in 800,000 years. Two thirds of current emission of methane are by products of human activity like oil and gas production, deforestation and raising farm animals. Together we emit 8 billion tons of carbon in 2007 alone. The evidence is overwhelming, that human activity is responsible for the rise of CO2 and methane and other greenhouse gases and that the increase is fueling the rise in global temperature.

What we have seen is that our earth has warmed due to human activity. Furthermore this phenomenon is accelerating. Between 1975 and 2005, CO2 emissions increase 70% over the natural interglacial levels and between 1999 and 2005 global emission accelerated at a rate of 3% per year. This climate change has already brought about great changes in the way we live.

Effects of Global Warming

• About half of the rise in sea level is due to thermal expansion. In addition oceans are rising because ice is welting. So far, most of that water has come from mountain glaciers and ice caps If Greenland ice sheet were to melt completely. there is enough water to raise the sea level by 7 meters, West Antarctica over 5 meters and East Antarctica 50 meters. If the earth were to lose just 8% of its ice, the consequences would be horrific – low lying cities like New York, London, Shanghai would be submerged.
• Low lying countries like the Netherlands, The Maldives, Indonesia are already finding their land inundated and there is danger of demographic changes with climate refugees moving to other countries, The lack of fresh water is effecting drinking water and agriculture For example, in the dry season, India nepal, vietnam, South China depend on rivers fed by Himalayan glaciers. The retreat of these glaciers threatens thee water supply of millions of people.
• Global warming has already resulted in change of climate. This has consequences on the agriculture, the world’s food production. The growing season for wheat grains had shifted to northern latitudes like Canada. A study published by the U.S. National Academy of Sciences has confirmed a rule of thumb among crop ecologists: for every rise of one degree Celsius above the norm, wheat, rice and corn yields fall by 10 percent.
• Expanding the arid areas of the Earth: Warming at the equator drives a climate system called Hadley Cell. Warm moist air rises from the equator, loses its moisture through rainfall, move north and south and then dry air falls to the Earth at 30 degree north and south latitude creating deserts and arid region. There is evidence that over the last 20 years Hadley Cell has expanded north and south by about 2 degree latitude, which may broaden the desert zones. Therefore drought may become more persistent in the American Southwest, the Mediterranean, Australia, South American and Africa.

Accelerating Climate Change

Over the last century the average rise in global temperature was 0.06 deg C per decade. Since the late 1970s, however, this rate has increase to 0.16 deg C per decade and 11 of the warmest years on record have occurred the last 13 years. The acceleration of global temperature is reflected in increase in the rate of ice melt. From 1963 to 1978, the rate of ice loss on Quelccaya in Peru was about 6 m per year. From 1991 to 2006, it averaged 60 m per year. Ten times faster than the initial rate. Ice retreat in between 2003 and 2009 in the Himalayas slowed slightly but loss in the mountains in the northwest increased markedly. So the average rate of ice melt in the region was twice the rate of 4 decades before. In the last decade, many of the glaciers that drain Greenland and Antarctica have accreted their discharge in the oceans from 20% to 100%.

Increasing rates of ice melt should mean an increasing rate of sea level rise. Over most of the 20th century, sea level rose about 2 mm per year. Since 1990, the rate has been about 3 mm per year.

So what is important is not just the Earth’s temperature is rising, but the rate of this change is accelerating. This means that our future climate may not be a steady gradual change, but an abrupt and devastating deterioration from which we cannot recover.

Tipping Points

Our climate system is a highly complex one which is very nonlinear. This means that a small change in one of the parameters could trigger off a large change through the various feedback systems. What is worrying is not so much that global warming is occurring, but it is ACCELERATING. This has caused many climatologists to warn that we may come to a tipping point when we are faced with an abrupt and devastating change in our climate system. So violent and sudden from which we cannot recover.

There exist many interacting positive feedback loops. For example:

• the ice albedo effect: ice melts, exposing darker areas beneath that reflect less solar energy, hence there is more absorption of heat, causing further ice melt.
• Higher temperature means tundra permafrost melts, releasing CO2 and methane from rotted organic material which in turn leads to higher global temperatures.

Sudden cold spells have happened in the past. The most recent one occurred around 5200 years ago which left its mark in many paleoclimate records around the world. The most famous evidence of this abrupt weather change comes from Otzi – Tyrolean ice man, whose remarkable preserved body was discovered in the Alps in 1991 after it was exposed by a melting glacier. Evidence suggests that Otzi was shot in the back with an arrow, escaped his enemies, then hid behind a boulder and bled to death. We know that within days of Otzi’s dying there must have been a climate event large enough to entomb him in snow, otherwise his body would have decayed or eaten by scavengers. Around the world there is evidence of this cold event as plants have been expose by melting glaciers in Quelccaya and Kilimaanjaro. The Soreq cave in Israel has recorded an abrupt cooling in the Middle East around 5200 years ago – the most extreme climatic event in the last 13,000 years.

An interesting article appeared in “Scientific American” called ” Did climate change doom the Neanderthals?” in 2009 . What are Neanderthals? One theory holds that Neanderthals were an archaic variant of our own species – homo sapiens, that evolved into or was assimilated by an anatomically modern European population. The other proposes that Neanderthals were a separate species – H. Neanderthalensis which the modern humans swiftly exterminated on entering their territory. It is established that neanderthals lived through both warm and ice ages. Recent data known as “isotope stage 3″ spans from 65,000 to 25,000 years ago At the beginning of this period Neanderthals were the only people in Europe. However, ‘oxygen isotope stage 3′ show that the climate became increasingly unstable heading into the last glacial maximum swinging severely and abruptly. With this flux came profound ecological changes: forest turning to grassland etc. Some evolutionary ecologists today believe that this swing in climate over the life time of Neanderethals could have pushed them into extinction.

Even if we stopped emitting greenhouse gases tomorrow, global warming will still be with us and temperature will rise for another 20 or 30 years. Once methane is injected into the troposphere, it remains there for about 10 years. CO2 stays 70 to 120 years as oceans have long thermal inertia. As to what future will bring, computer modeling like IPCC give temperature and other predictions like sea level rise, arctic ice cover all the way to to 2100. In our opinion, one has to look at the assumptions which are inputs to these codes. A major flaw, which has often been neglected in reports on IPCC results, consists of the human related time variations for the inputs for the future which are in principle not discernible. To describe the time dependence of of many parameters, the code has to assume certain emission characteristics for all variables which change the energy balance of the planet, such as CO2, methane, nitrous oxide, ozone etc. The best climate codes can do is to prescribe certain most likely values for these quantities as function of time. This has been concocted by a large number of scientists, economists and modern historians. For example, one of the 6 scenarios used by IPCC goes like this:

“Scenario B1 storyline and scenario family describes a convergent world with the same global population that peaks in mid-century and decline thereafter, as in A1 storyline, but with rapid changes in economic structures towards a service and information economy, with reductions in material intensity and the introduction of clean and resource efficient technologies. This emphasis is on global solutions to economic, social and environmental sustainability including improved equity, but without additional climate initiatives.”

It is difficult to believe that something as vague as this can correctly describe our future, In fact, the 6 different IPCC scenarios give widely different results for the end of this century. In our view we can may be predict up to the next 20 years, but no more.

Our Options

Briefly, one might say that our options are mitigation, adaptation and if we are only partially successful, then suffering.

We have put forth mass of evidence showing climate change is happening and not only that it is accelerating. Despite some awareness that we should reduce the burning of fossil fuel and use alternative energy like wind, solar, biofuel, nuclear, efforts in that direction are still minor and as a percentage of total electricity production, fossil fuel still occupy over 60% and there is no sign that our use is abating. At this junction in time, rather than further damage our already fragile ecosystems to satisfy demands for more energy, one should seriously consider a change in our life style and find ways to decrease the demand for energy.

We shall here point out only some important areas where changes may be made to reduce CO2 emission.

• Electricity generation. As percentage of total global electricity generation, wind 1.9%, biofuel 1.8%, hydro 15% and nuclear 13%. Only nuclear reactors can replace coal as steady baseload capable of generating 24 hours a day. For that reason it is indispensable. There are new IV generation ‘pebble bed’ reactors which are extremely safe in design. China is in the process of expanding the use of nuclear energy based on these new reactors.
• The percentage of CO2 emission by global transport is around 24 % and it is still rising even though we know oil is peaking. We should change to efficient urban mass transport systems, efficient electric and hybrid cars, reduce air transport as kerosene is on the wane. Use maglev trains.
• Conservation and efficiency in housing sector. Replace incandescent bulbs by Compact Fluorescent light (CFL) And LED. Much electricity can be saved by efficient design of buildings. This involves a stringent design methodology, solar orientation, superinsulation, advanced window technology, airtightness, ventilation, space heating and cooling.
• Around 2 gigatons of carbon is released into the atmosphere by deforestation. Taking carbon emission all together, the burning and degrading of fossil fuel contributes 7 gigatons. It is therefore very important to reduce deforestation, especially our precious tropical rainforests which form a cooling band that is the lung of our planet. Deferestation is now being recognized as a main cause of climate change.
• Already there is famine in Africa and this is going to get worse as 80% of the world’s population live at subsistence level. Any amount of food aid and medical assistance does not solve the fundamental problem, which is the world is over populated at 6.9 billion. Unless we decrease this number, all our efforts in reducing CO2 emission will be in vain because of the population pressure.