ROCKY REX'S SCIENCE BITES

Iceland lies on the  Mid-Atlantic Ridge , which is why it has volcanic activity. Iceland also has  ice caps  and  glaciers . Iceland is one of the fastest-warming places on the planet  – as much as four times the Northern Hemisphere average.  The glaciers that cover more than 10 percent of the island are losing an average of 11 billion tons of ice a year.                 Iceland glacial meltwater - photo Tom Harding The water melting from Iceland's glaciers would fill 50 of the world's largest trucks every minute. Parts of Iceland are rising as the ice caps melt,  reducing the weight on the Earth's crust. The thinning of the ice caps reduces the pressure on the rocks. Geologists know lower pressure from above makes volcanoes erupt more easily. Lower pressure allows volcanic gases to expand, and mantle rocks melt more easily at lower pressure as well. So more magma can rise into the volcanic systems. As that happens, Iceland's volcanoes may get mo

Farmers can put up with some bad weather, but  climate change  will make unusual events more likely. 20-30% of plant and animal species will be more likely to become extinct if the temperature rises by more than 1.5-2.5C. There will be big effects on farming from droughts and floods. The biggest effects will be seen first near the  Equator . Just  being near the Equator  makes it more difficult for countries to make economic progress. Hotter conditions affect how crops grow. Our agriculture is heavily reliant on  grasses  from the temperate regions. Corn, wheat, and rice  are all types of grass. The Tropics will expand as the world warms, so the world will find it harder to grow those important crops. People will  try to leave places  where they cannot produce enough food. Countries where  food prices  rise rapidly tend to become unstable, making  conflicts  more likely. Global warming affects wheat production. A rise of 2 degree C in tempe

Some key events in the discovery of climate change 1800-1870  Level of carbon dioxide gas (CO 2 ) in the atmosphere, as later measured in  ancient ice , was about 290 ppm (parts per million). Global temperature for 1850-1870 was about 13.6°C. 1824 Jean-Baptiste Joseph F ourier  calculated that the Earth would be far colder if it lacked an atmosphere.  1859 John Tyndall  discovered that some gases block infrared radiation.  He suggested that  changes in the concentration of the gases  could bring  climate change . 1896  Arrhenius  published first calculation of global warming from human emissions of CO 2 . 1930s  Milutin Milankovitch  proposed orbital changes as the cause of ice ages.  1938  Guy Callendar  showed that  global warming was underwa y,  reviving interest in the question.  1950s  By accident,  Russell Coope  discovered that some past climate change events happened in  just a few decades . This came from  his research into

An  ice sheet  is a mass of glacial land ice extending more than 50,000 square kilometres.  An  ice cap  is an area of land ice smaller than an ice sheet. The two ice sheets on Earth today cover most of  Greenland  and  Antarctica . An example of an ice cap  is  Iceland ’s  Vatnajökull. The ice sheets are now losing ice at the unprecedented rate of 500 cubic kilometres a year.  Scientists from the Alfred Wegener Institute (AWI) in Bremerhaven  mapped changes in the height of the Greenland and Antarctic ice sheets. They have found they are melting at record pace.  “Since 2009, the volume loss in Greenland has increased by a factor of about 2, and in the West Antarctic Ice Sheet by a factor of 3,”  says  glaciologist  Professor Dr. Angelika Humbert,  one of the study’s authors. A new NASA project called  Oceans Melting Greenland (OMG)   will observe changing water temperatures on the continental shelf surrounding Greenland, and how marine glaciers react to the presence

Some people say "The ice sheets in Antarctica are growing". This is very misleading. First, the Antarctic has ice on land and in the sea. Antarctica  is a continent covered by ice, unlike the ocean in the Arctic. The  sea ice  surrounding Antarctica melts almost to the coast each summer. The winter sea ice has increased by around 1% over the last few decades. This is due to complex processes. It is linked to  melting of the  land ice  on Antarctica ….. Antarctica is losing  very large amounts of ice  from its ice sheets and glaciers. The graph is from data collected by the  GRACE satellites. Here is an outline  of what is happening in the seas around Antarctica...... Seawater does not freeze until around minus 2 degrees C because it is salty. This effect of salt, of course, is used to help defrost roads. The meltwater off Antarctica’s ice sheets is freshwater. Freshwater has a low density, so  it forms a layer on top of the sea. Fresh

An  important scientific study  reports that  ocean life can take thousands of years  to recover  fro m climate change. The team, led by  Dr Sarah Moffitt,  examined more than 5,400 fossils, from sea urchins to clams, found in a 30 metre sediment core from the ocean floor off Santa Barbara, California. The tube-like sediment core is a slice of ocean life as it existed between 3,400 and 16,100 years ago. An example of an ocean sediment core. It provides a snapshot of what happened during the  last major deglaciation. It was a time of abrupt climate warming, melting polar ice caps, and expansion of low oxygen zones in the ocean. The sediment core revealed a history of a well-oxygenated sea-floor full of life. Then there was a period of oxygen loss and warming, that triggered a rapid collapse of life. A typical view of the ocean floor The study shows that  fossils nearly vanish  in layers formed when  oxygen levels  in the sea dropped. In periods of less than 100 years, o

Ice cores   are cylinders of ice, drilled from an ice sheet or a glacier.  They are usually 10 centimetres in diameter, and can be taken from deep in the ice. Ice cores provide  trapped samples of ancient air . Dr Emilie Capron of the   British Antarctic Survey   said - "Air bubbles trapped in ice are like little time capsules that record the past atmospheric composition.  "So we measure loads of different gases, and essentially we can measure greenhouse gases such as carbon dioxide and methane." Most ice core records come from  Antarctica  and  Greenland. Law Dome  is a location in Antarctica. The evidence in Law Dome ice cores shows that since the 18th century, when the Industrial Revolution began, the level of carbon dioxide has risen. It has changed from around 280 parts per million to 315 ppm when Keeling began his records in 1958. Now it has reached around 400 ppm, a rise of 85 ppm in just 56 years.   The longest ice cores are fr

The year  2014  ranks as Earth’s warmest since records began in 1880. This is reported by scientists from NASA and the National Oceanic and Atmospheric Administration. 9 of the 10 warmest years in the  instrumental record have now occurred since the year 2000. The exception was 1998, which was affected by a very strong  El Nino  event. That means nobody born since 1976 has experienced a colder-than-average year. 2014 was not even affected by an  El Nino,  which has been the case for previous record years. For a more complete picture of 2014, here is a link to a detailed report:   State of the Climate 2014.

Many people think  volcanoes  produce more carbon dioxide than humans. In fact, volcanoes produce far less carbon dioxide than humans. Geologists have checked this problem very carefully. This chart compares the average yearly production of carbon dioxide by human activities and volcanoes...... This information comes from the United States Geological Survey. Volcanoes would need a year to produce as much CO2 as human activity now produces in a few days . Not bad for a load of little mammals. Very large volcanic eruptions do affect global temperatures for a year or two. The second-largest volcanic eruption of the 20th century occurred at  Mount Pinatubo in the Philippines  on June 15, 1991. The volcano exploded in a cataclysmic eruption that ejected more than 5 cubic kilometres of material.  The ash cloud from this eruption rose 35 kilometres into the air. Nearly 20 million tons of sulphur dioxide were injected into the stratosphere in Pinatubo's 1991 e

This graph shows how temperatures have changed over the last 11,000 years, since the end of the last  glacial stage . The graph uses data from  modern temperature records , plus information about the past from  a research paper  that combined data from over 70 different scientific studies. The next graph adds data from even further back in time: The  green part  covers the time as  the last  glacial stage  was coming to an end, and the great ice sheets were melting. The last glacial stage ended about 10,000 years ago.  Then, for nearly 5,000 years, global temperature was  surprisingly stable .  In the next 5,000 years, up to about 1800, global temperature  declined  by about 0.7 deg.C. There were  some variations  in that slow decline: From 1800 until 2000, temperature  rose by about 0.8 deg.C,  according to the   World Meteorological Organisation. This chart shows the  annual average global temperatures  from NASA's  Goddard Institut

In the latest survey by Dr James Powell, 69,402 out of 69,406 climate change researchers accept human activity is the cause of global warming. What do scientists who research climate change say? Professor Tim Palmer FRS, Royal Society Research Professor in Climate Physics, University of Oxford: “T he threat of dangerous man-made changes to global climate is quite unequivocal.  It follows that if we want to reduce this threat, we must cut our emissions of greenhouse gases." Professor John Shepherd FRS, Ocean & Earth Science, University of Southampton: “The evidence is very clear that the world is warming, and that human activities are the main cause.  Natural changes and fluctuations do occur but they are relatively small." Professor Joanna Haigh CBE FRS, Professor of Atmospheric Physics, Imperial College London: “ The concentration of carbon dioxide in the Earth’s atmosphere now exceeds anything it has experienced in the past 3 million years and its