by Dr. Sherman Lewis, Professor Emeritus Political Science, California State University East Bay
Science, though often behind the actual pace of change, is still our best source of information. For the first time in the history of the earth, a species by its own conscious decisions is ending one geological epoch, the Holocene, and starting another, the Anthropocene.
credit: Planet Under Pressure
For decades, scientists have been discovering and warning about a series of interconnected threats to human welfare. In May 2013, the Millennium Alliance for Humanity and the Biosphere, consisting of more than 1,000 scientists, signed a consensus report at Stanford University that “Earth is reaching a tipping point.” “The evidence that humans are damaging their ecological life-support system is overwhelming,” said the report. “By the time today’s children reach middle age, it is extremely likely that the Earth’s life-support systems, critical for human prosperity and existence, will be irretrievably damaged.” Michele Marvier, chair of environmental studies at Santa Clara University, says that “humans dominate every flux and cycle of the planet’s ecology and geochemistry.”
A recent article in Nature stated “Localized ecological systems are known to shift abruptly and irreversibly, from one state to another when they are forced across critical thresholds. Here we review evidence that the global ecosystem as a whole can react in the same way and is approaching a planetary critical transition as a result of human influence.” Human “ ‘forcings’ far exceed, in both rate and magnitude, the forcing evident at the most recent global scale state shift, the last glacial-interglacial transition.” (Be sure to read the David Roberts and David Perlman articles from which the above quotes have been taken.)
From 1950 to 2012 world population tripled, to 7.1 billion, and continues to climb by more than 1.5 million people a week. The world population is expected to reach 9.6 billion by 2050. Joseph Speidel, a professor at UCSF’s Bixby Center on Global Reproductive Health, says, “The annual increment is rising quite dramatically. …We are still adding about 84 million people a year to the planet.” The addition in just 62 years will be greater than the human population growth for thousands of years to 1950. The World Resources Institute, an environmental think tank, estimates that by mid-century the world will need 70 percent more food, because as people grow wealthier they eat more meat, requiring more grain to feed livestock.
Falling birth rates do not quickly translate into falling growth rates because of “demographic momentum.” The absolute numbers keep rising for decades due to births to the large number of people in their child-bearing years. It took 12 years to add the last billion by 2011 and will take 14 more years to add the next billion, a slow decline in rate allowing a huge increase in numbers.
In developed countries falling birthrates are outweighed by the impacts of increased “problem consumption” per capita. Problem consumption refers to consumption which places the most stress on the earth. The United States is expected to grow from 313 million people to 400 million. California has 38 million people, including 10 million immigrants, and has grown 10 percent in the last decade. By 2050, projections show 51 million people living in the state, more than twice as many as in 1980.
In many less developed countries high population growth is being reduced somewhat by famine, hunger, disease, civil violence, and war. At least 2 billion people are malnourished, which increases death rates and reduces birth rates. Also, given lack of family planning, about half of unplanned pregnancies end in unsafe abortion. Nevertheless, in sub-Saharan Africa, Afghanistan and Yemen birth rates are exceptionally high. In 2012 U.N. demographers sharply raised their population projections, adding another billion people by 2100, reaching nearly 11 billion. African fertility rates have peaked at more than five births per woman. From now until 2050, poor countries will add the equivalent of a city of 1 million people every five days, said a report last year by the Royal Society, a top British scientific organization.
The Guttmacher Institute, a family planning research group, said more than 40 percent of the world’s 208 million pregnancies each year are unplanned. Half of U.S. pregnancies, about 3 million a year, are unintended, according to the National Campaign to Prevent Teen and Unplanned Pregnancy, a Washington advocacy group.
Population growth is primarily caused by the low status of poor women, especially in less-developed countries. Low status refers to a number of related problems—poverty, low education, lack of legal protections, lack of jobs, lack of health care and family planning, and abuse by dominant males. Rising status always lowers birth rates, regardless of ethnicity, religion, or culture.
The Guttmacher Institute said it would cost $4.1 billion a year in the $3.8 trillion U.S. budget to provide family planning for the 222 million women in the world who lack access to family health services. Republicans in the US Congress oppose funding that would allow poor women to choose how many children they have. In 2013 a House Appropriations panel again slashed money for family planning aid.
As human population waxes, the population of species in nature wanes. Scientists have identified the Anthropocene as the sixth mass extinction in the earth’s 540 million-year history. A quarter of known mammal species, 43 percent of amphibians, 29 percent of reptiles and 14 percent of birds are threatened. African elephants may be extinct within a decade.
Biodiversity is collapsing because of appropriation of biomass, habitat fragmentation, dewatering of rivers and wetlands, land conversion, pollution, invasive species, over-hunting, and over-fishing. Each year, humans appropriate up to 40 percent of the earth’s biomass, the product of photosynthesis, earth’s basic energy conversion necessary to all life. “Even in poorer nations that don’t have the impact that the average American has on the planet, population as it grows squeezes out other species because people need space to live, and the other species need space to live,” said Jeffrey McKee, an anthropologist at Ohio State University. Other wealthy countries have similar impacts, but less per capita.
California alone has 157 known endangered or threatened species.
People have altered the composition of the atmosphere by burning fossil fuels and causing emissions of other global warming gases like methane. Atmospheric carbon dioxide has increased from about 250 parts per million to about 400, and continues to rise. As the atmosphere holds more heat, temperatures rise, especially at the poles. The seasons move “pole-ward,” with earlier springs and later falls. Increased evaporation leads to more precipitation. On equatorial and temperate land masses, which have little water, droughts are increasing, as in the African Sahel. Increased heat energy in the ocean and atmosphere increases the intensity of extreme weather events. Glaciers, the Greenland Ice Cap, and the poles are melting. The permafrost is melting. More flooding occurs from precipitation, thermal expansion of the ocean, melt water from land-based glaciers, rising oceans, and extreme storms. Many species are affected, moving pole-ward if they can. Some species depend on altitude and run out of up. In the Monteverde Cloud Forest of Costa Rica, the golden toad ran out of mountain and was extirpated. Less sea ice is reducing polar bear population, which depend on it to hunt seals. Climate change reduces yields by decreasing rainfall in many large farming areas. Forest fires are increasing in extent and frequency.
To be covered in Part 2 on Thursday: Cheap Fossils to Auto-dependency and Misconceptions