Social driving forces and global environmental change

Human activities and global environmental changeDiana Liverman

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NASAGood morning. It is an honor to address this conference. Let us start in darkness. This composite image of lights at night across the world from 2003 is a powerful representation of humanity as a planetary force in the Anthropocene. The lighter areas are associated with more energy use and are where people are concentrated in cities. Because most of the electric light is produced by fossil fuels it also shows a geography of where pollutants and greenhouse gases are being emitted and an increasingly urbanized world where the proportion of people living in cities increased from about 30% in 1950 to the day in 2010 when the balance tipped to more than 50%. You can see the concentrations of light over eastern North America, Western Europe and Japan, and the scattered lights across India and Eastern China. Also shows the clusters of human activity along the coasts, including Australia, Latin America and Africa and suggests the potential vulnerability of those populations to sea level rise.2

The theme of this conference is of a Planet under Pressure, and humanity is now the major driver of environmental change. Each one of us has an impact on the biosphere through our use of resources and the waste we generate but some have a much greater impact than others. This photo is from the Live Earth concert in London in 2004 and reminds me of my own disproportionate impact because I arrived at the concert after an overnight flight from Johannesburg, contributing as much carbon dioxide in one day as a an average resident of India does in a year. The contrast between rising individual consumption and slowing population growth is one of the key points of my presentation which will analyze some of the social driving forces of global environmental change. Changing societyPopulation Growing but more slowlyEnergyGrowing but at lower carbon intensityDemand for land and foodGrowing especially in intensity and per capita and with some slowing or reversals of forest lossPoverty Inequality

I will begin with a brief review of the graphs of human activity that underpins the concepts of the Anthropocene and the great acceleration of resource use since about 1950. Then I will take a look at some important social trends in the last decade noting signs of hope as well as reasons for concern. For example I will argue that population growth, often thought of as the key threat to the planet is now slowing and that energy use, while increasing is doing so at a lower intensity. Demand for land is changing with the intensification of agriculture and changing diets are putting new pressures on the planet. Trade in virtual water and carbon is changing geographies of responsibility for degradation but may reduce overall impacts. And although poverty is decreasing, absolute and perceived inequality in incomes is increasing.I hope this will set the context for the talks by Will, Sandra and Tony and reflects some of the rich results from global environmental change programs that will be discussed throughout this conference.

4The increasing rates of change in human activity since the beginning of the Industrial Revolution.

Steffen W et al. Phil. Trans. R. Soc. A 2011;369:842-8672011 by The Royal SocietyHere, from a recent paper by Will and colleagues is a set of graphs that show significant increases in rates of change in human activity occur around the 1950s illustrating how the 50 years from 1950 to 2000 were a period of dramatic and unprecedented change in human history. Dont worry about the detail we will look at individual graphs in a minute. Just look at the overall trends which go steeply upwards Population increased from 3 to 6 billion in just 50 years, while the acceleration in economic activity was even more dramatic jumping 15-fold over that period. The post-war period has also seen the rapid expansion of international travel, electronic communication and economic connectivity. And even of Macdonalds restaurants.

Population

Global Population growth (1750 2010).Sources: US Census Bureau International Data Base 2011. .World Bank World Development Indicators 2011. Maddison. 2001. The World Economy: A Millennial Perspective. OECD. Here is the graph of human population growth - an indirect driver of resource consumption- since 1750 where you can see an inflection point around 1950 rising steeply to around 2000. What you do not see here is the slowing of growth as we moved into the 21st century a tremendously significant trend I will discuss later.

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I invite you to put a human face on population growth and consider the individual joys and sorrows that underlie a growing population. We know that people have children for many reasons including an essential human love for children and families, the fear of child mortality, the role of children as family labor and security for old age, and the inability of women to easily control their fertility. 7Fertility rates are falling (children per woman)There is an important trend in a key variable that you should be aware of. Since 1950 the average global fertility rate the number of children each woman will have has fallen dramatically from 5 to 2.5. The causes of this decline are multiple but include jobs and higher incomes for women, especially in urbanising areas, cultural changes and improved health and welfare for the elderly, and access to contraception. Millions of women have made a choice to have less children and although smaller families may have slightly higher consumption per capita this is going to reduce pressure on the planet. UN forecasts show fertility dropping below 2 by 2025 or so. Since replacement fertility is about 2.1 this means that population growth is starting to slow.8World population growth is slowingData from UNPOPIN, 2012This means there is a strong probability that population growth will level off around 9 billion and may fall thereafter. Although 9 billion is a lot of people, it is a driving force that has turned a corner so long as we maintain the improving status of women. It gives us a realistic target for efforts to provide water, food and energy sustainably to this population. 9

Total real GDPNordhaus (1997) The economics of new goods. University of Chicago PressIGBP synthesis: Global Change and the Earth System, Steffen et al 2004

GDP is another variable that shows rapid growth after 1950. Again, this is an indirect driver and translated into demand on non renewable resources or waste to make a link to pressures on the planet. Although there was a slight dip during the financial crisis reflected also in GHG emissions overall growth is of consumption is now growing again 10

There are also deep human desires behind the growth in GDP including the fulfillment of basic needs through the growth of agriculture and housing, for the variety offered by a diversity of consumer goods, and the drive to accumulate wealth to pass on to our children. To these we can add the fundamental characteristics of a capitalist economy such as the search for profit, the promotion of consumption and constant upgrading of goods, and the resource demands of a militarized world.11Changes in poverty 1981 to 2015

Chandy and Gertz, 2011, The changing state of global poverty from 2005 to2015, BrookingsIn 1980 more than 50% in extreme poverty $1.25 a day. Fell to 16% by 201012Changes in inequality within countries

www.oecd.org/els/social/inequality Incomes of top 10% growing more than poorest 10%zero (when everybody has identical incomes) to 1 (when all income goes to only one person) 0.28 in mid 1980s 0.31 nowWorld Bank 2006 inequality between countries doubled from 1820 to 1992 within stayed about the same 13

http://www.theoildrum.com/World Energy Consumption by Source, Based on Vaclav Smil estimates from Energy Transitions: History, Requirements and Prospects together with BP Statistical Data for 1965 and subsequent yearsAnalysis of long term data shows strong correlations between growth in GDP and energy consumption with the use of energy also increasing steeply since 1950, especially of coal, oil and natural gas. These fossil fuels produce the majority of anthropogenic greenhouse gas emissions. This poses three important questions for policy. Can we shift to energy sources that have a lower environmental impact? Can we delink economic growth from energy use? Or should we slow or reallocate growth so that we reduce overall consumption?14Decarbonization:Carbon dioxide emissions /GDP have fallenData from IEAThere is evidence of a weakening relationship between GDP, energy and carbon dioxide emissions as economies become more efficient or switch away from fossil fuels. Since 1971 emissions per unit of economic growth the carbon intensity of human activity has fallen from 0.8 to 0.5 and continues to fall. Over the period 1990-2007, CO2 emissions from energy use have decreased on average by 0.3%/year although the economic activity (GDP) increased by 2.3%/year. China plans to reduce their intensity by 17% from 2010 to 2015 planning to still grow but with lower impact per unit of growth.15Rise of renewables

http://www.ren21.net/Portals/97/documents/GSR/REN21_GSR2011.pdfThe worlds energy choices are also shifting, although slowly, in response to resource availability and cost and to policy incentives and social preferences. These graphs show increases in installed wind and solar capacity worldwide. Other shifts include a renewal of interest in nuclear energy and a strong commitment to efficiency in many countries. 16

Domesticated landAmount of land converted to pasture and cropland. Source: Klein Goldewijk and Battjes (1997) National Institute for Public Health and the Environment (RIVM). Bilthoven, Netherlands IGBP synthesis: Global Change and the Earth System, Steffen et al 2004

Another important social driver is the demand for land and for food. This graph represents the growth in domesticated land during the Anthropocene defined as land used for pasture and croplands. This has a gentler slope but still shows a shift after 1950 and that by 2000 more than 30% of the planets land had been converted to human uses. 17Forests returning in some countries

Lambin and Meyfroit, PNAS, 2011There are some interesting recent trends in land use that suggest a turnaround in deforestation in some countries. Recent research by scholars such as Lambin and Meyfroit and Morton and De Fries shows forest transitions and agricultural growth without deforestation. The top row of graphs from Erics work shows expansion of forests in China, Costa Rica, El Salvador and Vietnam despite growth in population. The causes of this transition include urbanization, agricultural intensification, and forest protection but Eric has also shown that in some cases such as Vietnam the forest loss has been displaced to neighbors such as Laos and Burma. Morton, De Fries et als recent paper shows that soybean production has grown on the southern border of the Amazon by taking over pasture land which is not displaced so as to cause more forest loss. However, in other regions, researchers are concerned that high food prices, and the reduction in conflict in central Africa may spur a new round of deforestation.18

Fertiliser consumptionInternational Fertilizer Industry Association (2002)IGBP synthesis: Global Change and the Earth System, Steffen et al 2004

Another indicator of human activity in the Anthropocene is the use of chemical fertilizers. This has grown from 50 to more than 300 million tons a year from 1950 to 2000. This allowed an intensification of agriculture that helped to feed people but also had a serious impact on the biosphere. We do see some fluctuation after 1990 and we will look at this in more detail. As we argue in an article that will appear in Bioscience, led by Ruth de Fries and Erle Ellis, fertlizer is one of several technologies that have increased food supplies and contributed to longer life expectancy, lower infant mortality and more choices and opportunities to pursue creative talents than at any time in history. The planet currently provides enough food for an adequate diet for the entire human population of approximately 7 billion people, although this co-occurs with an array of environmental challenges including nitrogen runoff, biodiversity loss and altered climate. That nearly one billion remain undernourished without access to this food is not the result of biophysical limits, but of social and institutional failure to implement solutions 19Growth in cereal production driven by yield not area intensification not extensificationData from FAOSTAT 2012Fertilizer applications, combined with plant breeding and other inputs, is one reason why growth in global cereal production since 1950 has been driven by increases in crop yields intensification rather than expansion of crop area. Looking forward this trend spares land for other uses, including nature, but only if intensification minimizes other impacts on the earth system.

20Changes in nitrogen use since 2000

Data from FAOSTAT 2012While agricultural inputs of chemical fertiliser and water have serious local and regional environmental impacts the latest date suggest that nitrogen use is falling in North America and Europe and is only growing slowly in South America. .21Geography of human influence

These problem with these graphs of global social drivers do not reflect the very varied geographies of human activity on the planet where some regions and people have a much larger impact than others. One way to look at this geography is through an index of human influence developed by WWF and CIESIN. The index combines population density and urbanization, distance to railroads, roads, rivers and coastlines, energy as embodied in nighttime lights and human land use to rank places from no human influence (green) to high human influence (red). You can see the regions of intense influence on the planet focused in Eastern North America, Central America, Europe, West Africa south of the Sahara, East Africa, South and South East Asia, Eastern China and Japan and the coasts of other continents.22Changing geographies of GHG emissions

http://www.youtube.com/watch?v=kqV-kx2ClXU

I could show several powerful animations that show how the timing and magnitude of these social drivers vary over history and geography but will just show one that uses data from Oakridge to illustrate the histories and geographies of carbon dioxide emissions since 1850. Starting from the industrial revolution in the UK in 1750 we see emissions increasing across Europe, then to North America and Japan by 1900. Remember these historical emissions have a long residence time in the atmosphere. By the end of the 20C we have high emissions in China, India, Europe and eastern North America but relatively little across Latin America and Africa. Here lies the core of the debate about responsibilities for climate change in relation to historical and per capita emissions.23GHG emissions and income in the UK

NEF 2011The main point I want to make here is that globally aggregated social drivers of global environmental change hide great variations in the role of different countries, but even more so, different people within a country. A recent study in the UK showed the emissions of the highest income earners to be three times that of the lowest. In countries with high income inequality the richest 10% of the population may be responsible for 50% of the greenhouse gas emissions and the growing middle classes of many developing or transitional countries are developing consumption habits that add to the burden on the earth system. 24Carbon is transferred in trade Emissions embodied in products (2004)Net exporting countries (blues) to net importing countries (reds)

Davis et al. 2011, PNAS; See also http://supplychainCO2.stanford.edu/

Recent research associated with several joint projects of the GEC programs has shown us that individual and country emissions, water and fertlizer use can be recalculated to account for trade - so that we can see how consumption of imports contributes to GEC and exports might reduce the impacts of consumption. This map from GCP shows the emissions embodied in products showing how carbon is transferred from China to Europe, Japan and the US and from the US to Europe.

Regional differences between where fossil fuels are burned and where goods and services that are supported by the energy that is generated are ultimately consumed, quantified by CO2 emissions (i.e. the net effect of emissions embodied in goods and services). The arrows depict largest interregional fluxes of emissions (Mt CO2 y-1) from net exporting countries (blues) to net importing countries (reds); the threshold for arrows is 100 Mt CO2 y-1. Fluxes to and from Europe are aggregated to include all member states of the EU-27.

25Water use is also transferred through trade in agricultural and industrial products 19962005.

Hoekstra A Y , Mekonnen M M. 2012. PNAS. 2012 by National Academy of Sciences

Similar calculations show the transfer of water through trade in agricultural products. Countries become importers and exporters of virtual water with US water exported all over the world. Mexico and Europe net importers. Virtual water balance per country and direction of gross virtual water flows related to trade in agricultural and industrial products over the period 19962005. Only the biggest gross flows (>15Gm3/y) are shown.Virtual water balance per country and direction of gross virtual water flows related to trade in agricultural and industrial products over the period 19962005. Only the biggest gross flows (>15Gm3/y) are shown.The total amt of water that would have been used if produced domestically was 2407 km3with trade the amount was 2038Thus the WORLD saved 369 km3 / year.The savings was equal to 18 % of global trade with agricultural products - and 4% of all agricultural production.This savings decreased from earlier calculations of 1997-2001 period (Chapagain et al 2006)where the savings were 28% of global trade and 6% of agricultural production.Take home messagesHumanity dramatically increased its use of resources and pollution since 1950There are some signs that some drivers are slowing or changingPopulation growth is slowing and will level offEnergy and carbon intensity is decliningAgricultural intensification and other factors is slowing or reversing deforestation in some regionsPoverty inequalityMany people still struggle to meet basic needs and aspire to increase consumption . A smaller proportion are consuming too much, including carbon, water and other resources embodied in trade

Humanity dramatically increased its use of resources and pollution since 1950There are some signs that some drivers are slowing or changingPopulation growth is slowing and will level offEnergy and carbon intensity is decliningAgricultural intensification and other factors is slowing or reversing deforestation in some regionsMany people still struggle to meet basic needs and many still aspire to increase consumption . A smaller proportion are consuming too much, including carbon, water and other resources embodied in trade

27Welcome to Future Earth Research for global sustainability

photos: www.dawide.com

Many presentations at the conference will explore these societal trends in more detail and some of you may disagree with analysis. But I hope I have demonstrated the significance of social drivers and social science in understanding GEC.I do hope that this week as we hear about the terrible pressures we are placing on the planet you will also search for signs of hope for planetary opportunities and reforms to earth system governance as described in papers we published in the last couple of weeks, for new integrated and interdisciplinary approaches to research that focus on sustainability such as the Future Earth initiative, and for signs that we are paying attention to the needs, vulnerabilities and potential of the poorest residents of the planet.

28Chart1137347151400811336050013256661174851234013941247412122187463734656114886902321892377643312017976244697355962461142648626016845832860104779642623799490372910805212265890045886541011429123412423810882989020124956973179371

North AmericaSouth AmericaWestern EuropeYearMillion tonsNitrogen Fertiliser Use

StatisticalData-5countries2000200120022003200420052006200720082009North America1373471513256661124741211148869012017976114264861047796410805212101142919890201South America1400811174851222187462321892244697326016842623799265890023412422495697Western Europe3360500340139437346563776433559624658328604903729458865438108823179371

StatisticalData-5

North AmericaSouth AmericaWestern EuropeYearMillion tonsNitrogen Fertiliser Use

Water use:Km3/ year% ofglobal% of agriculture% of trade

Global9087

Agriculture836092%

Trade203822%24%

Savings3694%18%