ROCKY REX'S SCIENCE BITES

Earth's polar regions are warming faster than the rest of the planet. One reason is that energy is carried to the poles by large weather systems. The  Arctic   includes an  ocean covered by sea ice . Arctic sea ice  melts in Summer and then refreezes in Winter. The area of Arctic sea ice is largest in March each year, and at its lowest each September. It is reducing over time - the graph comes from the US  National Snow and Ice Data Center. Research suggests   the remarkable decline of   Arctic sea ice over  the last century is far beyond anything seen for a long time.   The  Antarctic  is a  continent covered by ice , unlike the ocean in the Arctic. The sea ice surrounding Antarctica melts almost to the coast each summer. Ice shelves  around Antarctica are also affected by global warming. For a useful comparison of Antarctic and Arctic sea ice follow this link…… Arctic ...

There were some very unusual weather events in 2010, which may be a warning of future effects of climate change. Each time there are  extreme weather events , people debate "Is there a link to climate change?" It might be hard to prove in many cases. Some recent events, however, are extraordinary. The phrase  'weather on steroids'  has been used to describe these events. In 2010,  China  and  Brazil  had serious droughts, and in the first part of the year the Northern Hemisphere warmed fast, melting the winter snow cover very quickly. The picture shows the dried-up  River Negro  in Brazil, with a bridge in the distance.   But the biggest events were  the  heatwave in Russia  and the  flooding in Pakistan . In  Pakistan ,  Government officials said that from  July 28 to Aug. 3, parts of Khyber Pakhtunkhwa province recorded almost  12 feet (3.6 metres) of rainfall  in one week .  ...

Around 34 million years ago, at the  Eocene-Oligocene Transition  (EOT), the Earth was undergoing a period of global cooling.  Antarctica  changed from a green forested continent to the land of ice we know today.  The cooling was partly caused by  declining atmospheric carbon dioxide  levels, but it also coincides with changes in the geography of the Southern Ocean. This is an image of how this ancient world might have looked,  created recently by  Alan Kennedy  of the University of Bristol - Around 55 million years ago, CO2 levels rose during the  Paleocene-Eocene Thermal Maximum   (PETM). Weathering of the newly-building  Himalayas  caused CO2 levels to begin to fall. CO2 in rain makes a weak acid, which causes chemical weathering (especially of carbonate rocks like limestone, but of other rocks as well). Rivers carry the carbon compounds down to the oceans, where various processes (such as the fo...

Animals  are reacting to climate change very quickly. Some move to higher places,  others move north or south. Dragonflies  love warmer temperatures. UK dragonflies have mainly stayed in the south of the country, until recently. Ruddy Darter ( Sympetrum sanguineum ) Since 1980, 34 out of the 37 British species of dragonfly have expanded their range northwards by an average of 74km. That is over 2km per year..... nearly 6 metres per day. For example, the  ruddy darter  ( Sympetrum sanguineum ) and the  hairy dragonfly , ( Brachytron pratense ), have moved into north-west England.  This is evidence that the UK’s climate is growing warmer. "So much has happened to  dragonflies  in Britain since the 1990s that there is a most compelling case for the Government to adopt them as indicators of climate change", said  Steve Brooks . He is a London Natural History Museum research entomologist, with a special interest in the...

As global warming continues, heat goes into  all parts of the Earth's systems. The Earth is gaining more heat than it loses, and most of that heat is going into the oceans. More heat is going into the upper parts of  the oceans. The water in the oceans is expanding, which is one reason sea level is rising. The deepest oceans are still cold. Some of the heat is involved in melting ice, including Arctic sea ice. The recent reduction in Arctic sea ice is very dramatic. The  ice sheets of Greenland and Antarctica  are also melting.

The climate has changed before. When people say "It's changed before without people, so people can't be involved this time" ....think of  forest fires . Fires happened throughout time, does that mean people can't start fires? Ice ages, warm times ... the geological record in the rocks shows many events. Even so,  the current changes are very unusual . Note that in the "Years before present" scale, zero = 1950 AD Graph based on a  paper  published in 2013 The recent rise in temperature is very fast. What other kinds of changes are happening? Geologists   have compared the past with the present. This report - Climate Change Evidence: The Geological Society of London explains what they have discovered. This is based on part of that report: "Before the current warming trend began, temperatures were declining. This cooling took Earth’s climate into the ‘Little Ice Age’ (1450 – 1850).  Calculations indi...

The invention of the name  Greenland  may mark the start of the advertising industry. The  Saga of the Greenlanders  tells how  Erik the Red , the Icelandic Viking who wanted to get people to join his planned settlement, called it Greenland because a pleasant name would attract more settlers: He called the land which he had found Greenland, because, quoth he, "people will be attracted thither, if the land has a good name."  The  ice sheet  on Greenland covers most of this huge island. Greenland is losing ice, and the mass of ice lost is measured by satellites called GRACE. A survey of Greenland's glaciers  has shown they are speeding up. The speed has increased by about 30% in 10 years. 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 of warm, salty Atlantic water. Updates a...