Due to Human activities our planet has now reported to have entered into a “no analog state”. This means our planet has never experienced fast changing present-day conditions in its geological and evolutionary history. The closest geological event to what is happening now is known as (PETM) Paleocene-Eocene Thermal Maximum. PETM took place 56 million years ago. Changes happening now is way too fast, much faster than those in PETM. We are indeed in a no analog state in ecological terms. Welcome to the Anthropocene.
Anthropocene is a term coined by the prominent geologist Paul Crutzen meaning “The Age of Humans”. Systems on our planet are large and may seem immutable. However in a short amount of time, less than a Human life time, we have seen that we could introduce drastic changes. Perhaps the most striking one that made the news during the 1980s was the destruction of the ozone layer. Ozone hole over the Antarctic formed solely by our own activities.
https://www.nature.com/articles/d41586-019-01582-z
A geological time period must have a permanent stamp recorded in the rocks. Use of Nuclear bombs during the second world war and bomb tests during the cold war have generated a layer of radioactive material detectable in most rocks globally. Therefore a Human generated time stamp has already been made. Still, officially we are in the Holocene epoch. The discussion about a start date for the Anthropocene continues. Indeed there’s an official “Anthropocene Working Group” formed by scientists gathering candidate markers for the beginning of the epoch.
Our unprecedented use of fossil fuels and their chemical products are contributing to the formation of a Human activity layer. We can understand the extent of the problem by looking at how electricity is generated in US alone. We most certainly cannot continue by burning fossil fuels. Atmospheric CO2 levels are rising fast. In fact, you can check the most up to date atmospheric CO2 reading from Hawaii yourself.
It appears we have to wait a while until the promise of nuclear fusion (not fission) materialize. There are quite promising projects like the solar power station in Morrocco that will generate electricity by turbines using heat stored in molten salt. Hundreds of thousands of mirrors concentrate sunlight into a super heated core where regular good old table salt (NaCl) reaches temperatures above melting point of salt. Power generation method like in Quarzazate (*) is a firm answer to the type of questions such as: “oh what will we do when the sun goes down?”
Photo-voltaic solar panels are great to cover demand on site without the need for transmission. Thanks to photovoltaic technology, we don’t have to run a cable up to the
International Space Station – ESA (2012). Solar power stations could be an effective back up for times when the sun doesn’t shine.
(*) “Lawrence of Arabia” and “The Gladiator” were filmed in Quarzazate.
The scientific evidence behind global warming is very clear. How do we know that the Earth is in “no analog” state? Climate scientists calculate the mass balance of ice using satellite data and on site measurements. These measurements show whether the glaciers are growing or shrinking and help understand present day dynamics. Scientists also use “proxy data” to reconstruct climatic conditions in the past. When we say past we mean way long time in the past before humans began keeping temperature records. These “proxies” include tree rings, layers within ice cores drilled from glaciers and ice sheets, growth layers in coral, and layers of sediments from the bottoms of lakes and oceans.
Gases, dust, and other materials trapped in glacial ice provide many clues about climates of the past. Scientists dig ice cores from the Antarctic Polar Cap, the Greenland Ice Sheet, and glaciers around the world. Air bubbles in the ice capture miniscule samples of Earth’s atmosphere at the time the snow froze in the the past. These bubbles enable scientists to measure levels of carbon dioxide and other gases in prehistoric times. The thickness of ice bands tells us about past snowfall rates. Darkened layers of ice contain dust, providing further clues about past climates. Some ice core data from Antarctica provides information about climate to more than 800,000 years in the past, The climate record of this period shows at least 16 glaciations (see the vertical bars colored brown for cooling periods in the visual below) and 3 of them happened within the middle paleolithic period! Scientists continue to drill deeper older glacial layers going back to more than 1 million years.
The past is a template for the future. Intergovernmental Panel on Climate Change (IPCC) has released results of future temperature and precipitation simulations based on four different atmospheric carbon concentrations.
Cores drilled from the seabed also provide exciting data going back further to the beginning of the Eocene period 55 million years ago. A core drilled from the sea floor off Wilkes Land in East Antarctica provides a first clue about the past climate of this continent. More cores will help complete the picture.
Based on scientific measurements we now know that among all factors Human activities are dominating the major forcing leading to global warming. The following short educational clip sums it up concisely:
In June 2012, “Welcome to the Anthropocene” —a film about the state of the planet— opened the UN’s Rio+20 summit on sustainable development. The series was commissioned by International Geosphere-Biosphere Programme for the launch of the Intergovernmental Panel on Climate Change Working Group I as a summary for policymakers during the Fifth Assessment Report. It was funded by United Nations Foundation. Here we would like to breakdown all four sections individually to help convey its message more effectively. The film is also a part of the world’s first educational webportal on the Anthropocene. The narrative has an assertive tone conveying the urgency of the Human induced climate problem. The summit was the largest UN meeting to date.
The film takes us on a brief journey through the last 250 years of our history. Beginning from the start of the Industrial Revolution to the Rio+20 Summit. The expansion of humanity has become a global force equivalent in scale to major geological processes that shaped out planet. The film was also shown at the Planet Under Pressure conference in London.
The second part of the series is narrated by Edward Norton. The video takes viewers on a stunning satellite-viewed tour around our planet. By combining more than 10 datasets, and using GIS processing software and 3D graphic applications, the video shows not only where urbanization will be most extensive, but also how the majority of the expansion will occur in areas adjacent to biodiversity hotspots.
The video was produced to present the framework of a new book Global Urbanization, Biodiversity, and Ecosystems: Challenges and Opportunities — A Global Assessment. The scientific foundation of the Cities and Biodiversity Outlook project, the book presents the world’s first assessment of how global urbanization and urban growth impact biodiversity and ecosystems. It builds on contributions by more than 200 scientists worldwide.
More than half the Human population lives in urban centers. It is therefore very vital to turn cities into productive spaces. City farms and community gardens are among the positive examples. We must learn to be more productive in less area using less energy.
The third section of the series focuses on a crucial problem in a growing population: Water. NASA’s GRACE mission has revealed that Middle East and Pakistan-India Indus river are among the fastest groundwater loosing places. In North America, Ogallala aquafer that is crucial for agricultural productivity of the U.S. Midwest is showing signs of depletion.
Traditional water harvesting systems from the arid regions of the world is gaining attention. For instance, architecture developed by people living in Thar desert of India is an impressive example for Human resilience and adaptations to cope with harshness of nature.
The fourth and final part in the sequence summarizes the state of the science on global warming. Narrated by Sarah Sherborne, the documentary uses extensive data sets and models generated by many institutions around the World. These include: GEOS-5 atmospheric model, NASA/Goddard Space Flight Center Scientific Visualization Studio, Suomi NPP VIIRS Nighttime Lights 2012, Earth Observation Group, NOAA National Geophysical Data Center, Landscan 2011tm High Resolution global Population Data Set, UT-Battelle, LLC, Oak Ridge National Laboratory, Blue Marble: Next Generation (Reto Stöckli), NASA Earth Observatory, NASA Goddard Space Flight Center, Annual temperature anomaly compared to 1860-1899 period, GFDL-CM3 (historical and RCP8.5 experiments) 1860-2100, Coupled Model Intercomparison Project Phase 5 (CMIP5), September sea ice concentration, Sea level rise flooded areas, Centers for the Remote Sensing of Ice Sheets (CReSIS), Cyclone tracks by International Best Track Archive for Climate Stewardship (IBTrACS), Ocean acidification Max Planck Institute Earth System Model.
Scientists have outlined 9 planetary boundaries within which humanity can safely operate without endangering global life support systems. Unfortunately, 4 of the thresholds have already been crossed. One of them is ocean acidification due to sharp increase in atmospheric CO2 concentration. Increasing acidity makes ocean water corrosive dissolving the calcium shells of marine organisms which will affect fisheries by disrupting the very base of the food-webs.
National Science Foundation has produced a series of videos as educational resources about the climate change.
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