ROCKY REX'S SCIENCE BITES

Space is not very far away. Aircraft on long-haul flights travel at a height of about 10 km. The lowest layer of the atmosphere, the  Troposphere,  ends at about 15 km. The air in the layers above the troposphere is very thin indeed. Think of a place around 15 km (9 miles) from where you are. That's pretty much how near you are to space. All the waste gases people dump into the air are trapped in the thin layer of air around the Earth. Molecules  in the air include nitrogen and oxygen as well as water, carbon dioxide, ozone, and many other compounds in trace amounts, some created naturally, others the result of human activity. In addition to gases, the atmosphere contains extras such as smoke, dust, acid droplets, and pollen. Atmospheric concentrations   of some   greenhouse gases   over the last 2,000  years.  Increases since about 1750 are due to human activities in the industrial era.  Concentration units are  ...

Between about 20,000 and 5,000 years ago, Earth slowly changed from the frigid conditions of an  Ice Age , to the world on which our civilization has developed. As the  ice sheets  melted, colossal volumes of  water  flowed back into the oceans. The  pressures  acting on the Earth's crust changed as a result.  The  weight of ice  on the continents was reduced, and the rising seas put  extra water pressure  on the seafloors. In response, the  crust  moved up and bent, creating extra volcanic activity, increased seismic shocks and giant landslides. So if we continue to allow greenhouse gas emissions to rise unchecked, causing serious warming, will our planet's crust react once again? In Alaska, climate change has pushed temperatures up by more than 3 degrees Celsius in the last half century, and  glaciers  are melting at a staggering rate, some losing up to 1 kilometre in thickness in the last 10...

Hurricanes, cyclones, and typhoons are all the same weather phenomenon. We use those different names for these  tropical storms  in different places.  In the Atlantic and North-East Pacific, the term  “hurricane”  is used. So far,  Hurricane Patricia  is the strongest hurricane recorded at landfall.  Image of Hurricane Patricia tweeted by  astronaut Scott Kelly . In the North-West Pacific a tropical storm is called a  “typhoon” , and  “cyclones”  occur in the South Pacific and Indian Ocean. Three strong tropical storms  (Kilo ,  Ignacio , and  Jimen a) ,  formed in the Pacific in 2015.  On Sunday 30th August, all of them were a category 4.  This was the first time the north-eastern Pacific had seen three category 4 hurricanes at the same time. Multiple cyclones in the Pacific Ocean in 2015 Tropical storms  can’t form outside the tropics - water temperatures are too cold. Sea su...

Marlin  can hunt in water a half mile down, and sailfish often dive deep too. In more and more places around the world, ocean predators are sticking near the surface. Why? Warming temperatures are  sucking oxygen out of waters  even far out at sea, making enormous stretches of deep ocean hostile to marine life. Vast stretches of the ocean interior  suddenly lost oxygen  during the transition out of the last  glacial stage , between 17,000 and 10,000 years ago.  This event was the most recent example of large-scale global warming.

This graph shows how  carbon dioxide  has increased and decreased over hundreds of thousands of years. The low readings match with times called ' glacial stages '. During glacial stages,  ice  covered large areas of the Earth. The peaks in the graph show times when carbon dioxide was high, matching times called ' interglacial stages '. The most recent glacial stage occurred between about 115,000 and 11,500 years ago.   The  last interglacial period  occurred before it, from around 130,000 to 115,000 years ago. It's official international name is the  Eemian,  but it has other names in specific places. Climate information from that time is particularly useful. During that time,  temperatures  on earth were higher at the poles than they are now.  The  sea level  was between five and nine metres higher than current levels, because of the melting of ice in  Greenland  and  A...

The climate can react to sudden shocks. The weather in  1816  was very strange.  Spring arrived, but then everything seemed to turn backward, as cold temperatures returned.  The sky seemed permanently overcast.  T he lack of sunlight became so  severe that farmers lost their crops. Food shortages were reported in Ireland, France, England, and the United States. 1816 became known as  "The Year without a Summer"  or "18-hundred-and-frozen-to-death". It was over 100 years before anyone understood the reason for this weather disaster. The eruption of an enormous volcano on a remote island in the Indian Ocean a year earlier had  thrown enormous amounts of volcanic ash  into the upper atmosphere. The dust from  Mount Tambora , which had erupted in early April 1815, had shrouded the globe.  With sunlight blocked, 1816 did not have a normal summer. In Switzer...

Oil is a  fossil fuel . It was formed from chemicals from ancient living things. To make the chemicals in oil, the  temperatures  and  pressures  needed to be just right. The oil (and gas) will only stay in the reservoir if there are  suitable structures  in the rocks: The carbon compounds from the plants and animals have been trapped for hundreds of millions of years. They have been burned to make carbon dioxide in a very short time. The amount of carbon dioxide in the air has changed very quickly. Diagram of how oil is made Source:  Library and Archives Canada © Library and Archives Canada

What is the  worst-case scenario  for climate change? The geological record shows that when the atmosphere suddenly changes, there are big effects on living things. Every time in the geological past that gigatonnes of CO2 entered the atmosphere, the changes were very significant. The geological record contains examples of major temperature changes, associated with changes in atmospheric CO2. Events in which the temperature rose by several degrees in a geologically short time are called  hyperthermals. For example, the   PETM , around 56 million years ago: Matthew Huber at Purdue University calculated that warming slightly in excess of 10 degrees C—like that of the PETM and of pessimistic scenarios for future fossil-fuel burning—could render large portions of the planet uninhabitable for many creatures.  He has said : "There used to be subtropical forests near the poles 50 million years ago, and that doesn’t sound so bad. "But the fossil re...

What is the worst-case scenario for climate change? The geological record shows that when the atmosphere suddenly changes, there are big effects on living things. Five major   mass extinction   events are recorded in the rock record of the last 600 million years. The biggest extinction was at the end of the   Permian ,  around 252 million years ago. It is called the   End-Permian mass extinction. Only about 8% of species survived to live on in the Triassic Period. This photo shows geologists investigating tilted sedimentary rocks at Shangsi in South China. Triassic rocks (at the top right) lie over the older Permian rocks. Researchers have found evidence of a compound called fly ash, one of the products of coal combustion, in rocks laid down just before this extinction event.  A large amount of coal had been burned over a period of tens of thousands of years. The  coal was burned by volcanic eruptions ...

Lots of people discuss ' climate change '. 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 .... rainfall in Ireland. 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 ...

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...