ROCKY REX'S SCIENCE BITES

It is often claimed that the  Sun  is causing global climate change. The Sun  is  the source of the heat on the Earth, but  it has not suddenly become more active recently. The Sun may be going into a phase of lower activity - but that will not reverse global warming. When the Sun's energy arrives at the Earth, it travels through the air. Some is reflected back to space, but some hits the Earth and warms it. The warm Earth gives off  infrared radiation  with various wavelengths.   Some of those waves can pass back out of the air to space, but some are absorbed by certain gases in the air. The gases then re-emit the energy into the air. If there are more of those gases, less heat escapes into space, so the Earth warms. In the graph below, from the  Stanford Solar Center , carbon dioxide data comes from the Law Dome ice core in Antarctica, and from the observatory on Mauna Loa in Hawaii. The Earth h...

Heavy rainstorms caused devastating flooding across a 12-county region of West Virginia in late June 2016. In February 2020, the UK was hit by 3 major storms and many parts of the country had well over twice the average rainfall for the month, resulting in significant flooding in many river valleys. One of those storms was  Storm Dennis. Events like this are almost certainly made more frequent, and more intense, by global warming.  Climate scientists have  said  that the overwhelming scientific evidence shows that the warming of the planet’s atmosphere is increasing the occurrence of, and the seriousness of, heavy rains. Warmer air holds more water, leading to stronger and more frequent heavy precipitation events.  This is confirmed by research done by  a team of scientists of the Potsdam Institute for Climate Impact Research. They find the worldwide increase to be consistent with rising global temperatures, caused by greenhouse-gas emissions from...

Some people claim the current climate change has " natural causes ". They talk about the changes during the  'Ice Age' , thinking the current events must be natural as well. Scientists say that is not the case. The current situation is different. The things that caused the changes in the Ice Age are not exactly the same this time. The graph below shows that carbon dioxide in the air has increased and decreased over hundreds of  thousands of years. The  recent increase in carbon dioxide is much bigger and faster  than the natural changes. The low readings match with times called  'glacial stages'. During glacial stages, ice covered large areas of the Earth. The most recent glacial stage occurred between 115,000 and 11,500 years ago.  The peaks in the graph show times when carbon dioxide was high. Those times are called  'interglacial stages' .   Glacial and interglacial stages are linked to regular patterns in the movements of the ...

Sea level is rising , and there are several reasons connected to  global warming . An international team of researchers  has produced this graph of ocean levels, for a period of time going back to around 500 BC.  Extra water enters the sea when  ice melts  from Antarctica, Greenland and other glaciers and ice caps. Recent research suggests that  the glaciers of Alaska alone now contribute 75 gigatonnes per year. S eawater also expands  as it gets warmer, just like the liquid in a thermometer expanding as temperatures rise.  This is called 'thermal expansion.' Investigating sea level rise involves scientists using many different methods, including satellites which map the surface of the sea. It is also important to look carefully at older records from tidal gauges all over the world. Global sea level rise from the 20th century to the last two decades has speeded up even more than scientists previously thought, according to  a ...

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.  1856 Eunice Foote   describes filling glass jars with water vapour, carbon dioxide and air, and comparing how much they heated up in the sun. “The highest effect of the sun’s rays I have found to be in carbonic acid gas,”    “The receiver containing the gas became itself much heated – very sensibly more so than the other – and on being removed, it was many times as long in cooling.” 1859 John Tyndall  discovered that some gases block infra-red radiation.  He suggested that  changes in the concentration of the gases  could bring  climate change . 1896  Arrhenius  published the first calcu...

Average global temperature  is now higher than it has been for a long time. Graph by Klaus Bitterman. Green dots show the 30-year average of the  PAGES 2k reconstruction.   The red curve shows the global mean temperature, based on  HadCRUT4  data from 1850 onwards.  In blue is the original "hockey stick" from  a  paper by Mann, Bradley and Hughes (1999)  with its uncertainty range (light blue).  The green dots are calculated using data from many places around the world, using information from a range of  temperature proxies , such as documents, ice, lakes, pollen, tree rings, corals, seabeds and  speleothems. PAGES is the  Past Global Changes  programme launched in 1991. 

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...