This page is devoted to presenting bite-sized presentations of data and information about the major environmental and social trends that will define the 21st century. Trends presented will cover a range of topics including our resources such as land use, water availability, fisheries… to geopolitical factors such as population growth and distribution… to environmental changes like climate change.
TREND: A warmer world
Commitment to 1992 United Nations Framework Convention on Climate Change (UNFCCC) was a commitment to achieving: “in accordance with the relevant provisions of the Convention, stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system.” A 2°C warming of average global temperature is the internationally agreed ceiling above which the impacts from climate change are considered highly detrimental environmentally, socially and economically. It has generally been assumed that this would occur if greenhouse gas concentrations rose above 550 ppm carbon dioxide equivalent. This assumption, however, has been called into question. Some suggest that there is only a 50% chance of keeping to this ceiling if greenhouse gas concentrations were stabilised to 450 ppm and that only by stabilising below 400 ppm would average global air temperatures highly likely not exceed 2°C.
Carbon dioxide concentrations recorded at Mauna Loa have for the first time topped 400 ppm. This has also been observed at several stations of the World Meteorological Organization’s Global Atmosphere Watch network.. Average global CO2 concentration, according to WMO’s Greenhouse Gas Bulletin, reached 390.9 ppm in 2011, or 140% of the pre-industrial level of 280 ppm. At the current rate of increase, the global annual average CO2 concentration is set to cross the 400 ppm threshold in 2015 or 2016. Reports published last year all suggest that we are on track for a 4°C warmer world by 2100 because our efforts to mitigate have thus far been ineffective, while population growth and industrialisation in developing countries counter efforts made.
Global temperature projections, IPPC AR4 2007. A1F1 scenario represents a world of rapid economic growth along with rapid introductions of new and more efficient technologies but still heavily fossil-fuel based.
TREND: 3 billion more – and older
Based on the UN 2010 Revision of World Population Prospects, world population is expected to increase to 9.3 billion in 2050 and to reach 10.1 billion by 2100 “contingent on the continued decline of fertility in countries that still have fertility above replacement level (that is, countries where women have, on average, more than one daughter) and an increase of fertility in the countries that have below-replacement fertility. In addition, mortality would have to decline in all countries” (medium fertility variant in graph below). Of those 9 billion in 2050, 2 billion will be over the age of 60.
From the UN Department of Economic and Social Affairs, Population Division, Report “World Population Ageing: 1950-2050″ 2001