ROCKY REX'S SCIENCE BITES

Some people confuse 'climate' with 'weather' - but i f 'climate' and 'weather' are the same, why would there be two words? Other people say "We call climate change 'winter' and 'summer'...."   What does the word ' climate ' mean? It normally means  the average of conditions over 30 years . Climate  normally means 'an average over 3 conventional decades'. A  conventional decade  is, for example, 2001-2010, or 1961-1970. So ..... 3 full, conventional decades......such as 1981 to 2010. For example .... average temperature in Ireland, 1961-1990: And another example -  ' A verage temperature 1951-1980' The definition of 'climate' goes back at least 100 years. So if we are discussing  climate change , that is what 'climate' means. But in recent times, there has been a lot of variation in global temperatures. So it can be useful to look at  single conventio...

Carbon dioxide  levels in the atmosphere are rising. This graph showing the data is called the  Keeling Curve . The small up-and-down pattern is caused by changes during each year -  in the summer in the northern hemisphere, there is more photosynthesis which causes CO2 levels to fall. The Keeling Curve is named after the scientist who first produced accurate measurements of carbon dioxide in the air -  Charles David Keeling.     Charles David Keeling in the lab. Keeling's collection of data began in 1958. Concentration is measured in  p arts  p er  m illion (ppm) March 2015 was the first time for hundreds of thousands of years that CO2 exceeded 400 ppm for a whole month. Ice core data  shows humans have never breathed air containing so much CO2. Since Keeling began recording, CO2 has risen from 318 ppm to 400 ppm... a rise of around 25%.   The fastest rise of CO 2  in the air seen in   the ice...

According to the  Royal Society ....... If human emissions of CO 2  stopped altogether... .... it would take thousands of years for atmospheric CO 2  to return to ‘pre-industrial’ levels. " The climatic impacts of releasing fossil fuel CO 2  to the atmosphere will last longer than Stonehenge, " says  University of Chicago oceanographer  David  Archer. "Longer than time capsules, longer than nuclear waste, far longer than the age of human civilization so far." Why is that? It takes a long time for deep oceans to bury the carbon dioxide in ocean sediments.  Lifee on the abyssal sea floor (depths ranging from 4000-6000 m) near the Hudson Canyon off the coast of New Jersey. Photo taken using the Deep Submersible Research Vessel (DSRV)  Alvin's camera system.  Image courtesy of Deep East 2001, NOAA/OER. Surface temperatures would stay high for at least a thousand years. Humans would face  a warmer planet due to past and curre...

The  Arctic   includes an  ocean covered by sea ice. Arctic sea ice  melts back 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 graphs come from the US  National Snow and Ice Data Center. The NSIDC also publish this graph, which is normally updated every day. More graphs and other data are also available from the  Arctic Data Archive System , operated by the Japanese  Arctic Environmental Observation Center. The total volume of Arctic sea ice has declined dramatically over time. New research   shows the decline in Arctic sea ice area since 1850: Research suggests   the remarkable decline of   Arctic sea ice over  the last century is far beyond anything seen for a long time.   Average Arctic temperatures have risen by around 6 C degrees since the 1960s. ...

The  permafrost  of places like  Siberia  is not so permanently frozen any more. As it slowly melts, wonderful things are emerging, some frozen for tens of thousands of years. Baby mammoths  are sometimes found in an extraordinary state of preservation. "As the Earth warms, scientists worry that some of the carbon in permafrost could escape to the atmosphere as carbon dioxide or methane.  Increasing the amount of these gases in the atmosphere could make Earth's climate warm up even more." Arctic permafrost – ground that has been frozen for many thousands of years – is now thawing because of global climate change.  There are many effects of global warming, including melting permafrost, discussed in this useful document:  Physical effects of warming. The results of melting permafrost could be  disastrous and irreversible.

Scientists have   observed an increase in carbon dioxide’s greenhouse effect   at the Earth’s surface.    The graphs show carbon dioxide’s increasing greenhouse effect at two locations.  The first graph shows CO 2  radiative forcing measurements obtained in  Oklahoma .  The second graph shows similar upward trends in  Alaska . (Credit: Berkeley Lab) The researchers link this to rising CO 2  levels from fossil fuel emissions. Radiative forcing  measures how the planet’s energy balance is altered by atmospheric changes.  Positive radiative forcing  occurs when the Earth absorbs more energy from solar radiation than it emits as heat radiation back to space. “We see, for the first time in the field, the amplification of the greenhouse effect because there’s more CO 2  in the atmosphere to absorb what the Earth emits in response to incoming solar radiation,” says Daniel Feldman. Dr Feldman is a  sc...

Burning  fossil fuels  produces  carbon dioxide . Carbon dioxide emissions  need to be limited.   However, the potential carbon dioxide emissions contained in fossil fuel reserves are vast. So   it's not possible for all current fossil fuel reserves to be used,  if the Earth's warming is to be kept below 2 °C.  This huge excess quantity of fossil fuel is sometimes called the  'Carbon Bubble'. However, there are   major objections  even to the "two-degree limit" . Many say the number is simply too high. Archbishop Desmond Tutu has  pointed out   that a two-degree global average rise might result in Africa’s temperature rising as much as 3.5 degrees—a potentially disastrous change. Various scientific research projects have looked at what would happen if all the fossil fuels were burned. One project concluded: The Antarctic Ice Sheet stores water equivalent to 58 metres in global sea-level rise....