The clothing, weapons and other items found with the body give a glimpse into life when metal was first being used.
Tests later confirmed the iceman dates back to 3,300 BC. He probably died from a blow to the back of the head. His body was so well-preserved that scientists were able to determine that his last meal was red deer, herb bread, wheat bran, roots and fruit. He lived at a time, over 5,000 years ago, when the Earth was starting to cool.
So when he died high in the mountains, his body became covered with snow. Modern warming (shown by the red part of the graph) made it possible to find him.
The 2017 average global temperature across land and ocean surface areas was: ..... 0.84°C above the 20th century average of 13.9°C, behind the record year 2016 (+0.94°C) and 2015 (+0.90°C, the second warmest year on record). 2015 and 2016 were both influenced by a strong El Niño episode.
Every place on earth experiences 12 hours of daylight twice a year, on the Spring and Autumn Equinox. The Sun is at its lowest path in the sky on the Winter Solstice. After that day, the Sun follows a higher and higher path through the sky each day, until it is in the sky for exactly 12 hours. On the Spring Equinox, the Sun rises almost exactly in the east, travels through the sky for 12 hours, and sets almost exactly in the west.
The March equinoxmarks the moment the Sun appears to cross the celestial equator – the imaginary line in the sky above the Earth’s equator – from south to north. After the March equinox, northern days continue to lengthen until the June solstice.
Carbon dioxide is always in the atmosphere as part of the Earth's carbon cycle. The global carbon cycle transfers carbon through the Earth’s different parts - the atmosphere, oceans, soil, plants, and animals. So carbon moves around — it flows — from place to place.
Carbon sinks cope with about half of human greenhouse gas emissions.
The other half has accumulated in the atmosphere.
Daniel Rothman, Professor of geophysics in the MIT Department of Earth, Atmospheric and Planetary Sciences and co-director of MIT’s Lorenz Center, has identified “thresholds of catastrophe” in the carbon cycle that, if exceeded, would lead to an unstable environment, and ultimately, mass extinction.
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.