Hotter sooner faster: Global temperature changes over the past 136 years

Graph of global temperature anomaly from 1880 to 2016
Global temperature anomaly, 1880 to present

This graph shows the global temperature anomaly: how current temperatures compare to latter-twentieth-century “normal” temperatures. Normal, here, is the 1951-1980 average.

in looking at the global temperature data, three things are apparent. First, the Earth is already warming. The graph has been trending strongly upward since at least the 1980s. Second, the increase in temperature from the 1951-1980 baseline period will soon reach one degree Celsius. Indeed, temperature outliers such as those in February and March 2016 are approaching 1.5 degrees. Temperatures are rising fast—charting significant increases in decades, not centuries. Third, there is in the data-points a suggestion that the curve may be getting steeper; temperature increases may be accelerating. It’s too early to tell, but given that global temperature increases are lagging well behind atmospheric greenhouse gas (GHG) increases, and given that global emission rates continue to increase, it is prudent to consider that temperature increases may accelerate beyond already-rapid rates.

How high might temperatures go? Here’s what we know. In the lead-up to the 2015 Paris climate talks, nearly every nation submitted to the United Nations a commitment to reduce GHG emissions. The United States committed to reduce its emissions by 26 to 28 percent (below 2005 levels) by 2025. Canada committed to reduce emissions by 30 percent by 2030. Other nations made comparable commitments. But the climate models show that even if every nation meets its emission-reduction commitments, our Earth will warm this century by 3.2 degrees Celsius—well beyond the so-called “dangerous” level of 2 degrees C, and more than double the 1.5 degree mark discussed in Paris. Indeed, the graph above makes it clear that 1.5 degrees was always pure fiction. In order to avoid a temperature increase of 3.2 degrees, we must set and meet more ambitious targets.

Climate science can be complicated. But at a public policy level—at the levels of citizens and legislators and democratic governance—climate change is simple and clear. It is happening. It is happening fast. And it will devastate our cities, economies, food systems, ecosystems, and perhaps even our civilization unless we act fast. Simple.

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Graph sources: Combined Land-Surface Air and Sea-Surface Water Temperature Anomalies from National Aeronautics and Space Administration (NASA) Goddard Institute for Space Studies (GISS): GISS Surface Temperature Analysis (GISTEMP).

It’s gonna get hot: Atmospheric carbon dioxide over the past 800,000 years

Graph of atmospheric carbon dioxide levels for the past 800,000 years
Atmospheric carbon dioxide concentrations, 800,000 years ago to present

There are lots of graphs related to climate change. Only a few, however, get to the core of the issue. This is one such graph. It shows atmospheric carbon dioxide (CO2) levels over the past 800,000 years—a period four times longer than our species, Homo sapiens, has walked the Earth. The units, parts per million (ppm), will not be familiar to everyone. But the units aren’t important. What is important is the shape of the graph, and the magnitude of current CO2 levels relative to those in the past.

As the graph shows, over the past 800,000 years, atmospheric carbon dioxide levels have risen and fallen. Low concentrations correspond to ice ages—eight such periods are visible in the graph. Higher CO2 levels correspond to largely ice-free “interglacial” periods. The critical point is this: in the 800,000 years before the modern era, CO2 levels never once rose above 300 ppm. Not once. Now, however, CO2 levels are 405 ppm. And because our emissions continue, it is likely that atmospheric concentrations will increase past 500 ppm, maybe past 600 ppm. Temperature increases are lagging behind CO2 increases. As Earth’s temperatures rise to “catch up” with the rapid increase in CO2, it’s going to get very hot. And it is going to stay hot for a long time.

There can be no doubt: humans are the cause of the rapid rise in CO2 levels. No one can look at the graph above and come to any other conclusion. The years 1800 and 1900 are highlighted. The fossil-fuelled industrial and transportation revolutions of the 19th, 20th, and 21st centuries are clearly visible in the graph’s vertical spike—an increase in atmospheric CO2 that has proceeded further and faster than at any other time in the past 800,000 years.

CO2 levels have increased by 100 ppm in a century. The data shows that such an increase usually takes 10,000 years. Humans are causing CO2 levels to rise 100 times faster than those levels rose at any time in the past 800 millennia. Even worse, the rate of increase is accelerating; at current and projected emission rates, the next increase of 100 ppm may take just 40 to 60 years.

It is impossible to overstate the danger of what we are doing. Words cannot convey how damaging continued CO2-level increases will be to the long-term prospects for human cities, societies, and economies, or to other species and the natural ecosystems we all rely upon. It is as if we have decided to set fire to our home, the Earth. Unless we extinguish that fire, all we hold dear will perish. Currently, we are pouring on gasoline.

Note: CO2 measurements for recent decades come directly from air samples. Measurements for past centuries come from analysis of air trapped in bubbles in Antarctic ice. Each ice core is analyzed at multiple research facilities using multiple techniques. Because of this duplicate testing and diversity of sampling methods, there is high confidence among scientists that ice-core data accurately reflects CO2 levels in previous centuries.

Graph sources:
– 800,000 years ago to 1913: Ice core samples, Dome C, Antarctica (Monnin et al. 2001; Siegenthaler et al. 2005; Luethi et al.) and Vostok, Antarctica (Petit et al. 1999; Pepin et al. 2001; Raynaud et al. 2005)
– 1832 – 1978: Ice core samples, Law Dome, Antarctica
– 1959 – 2013: Direct atmospheric measurements, Mauna Loa Observatory, National Oceanic and Atmospheric Administration (NOAA)

Too much tourism: Global air travel and climate change

Graph of global air travel, in trillions of passenger-kilometres, historic, from 1936 to 2016
Global air travel, trillions of passenger-kilometres per year, 1936-2016

The graph above shows that global air travel is increasing exponentially. In 2016, business travelers, tourists, and others traveled more than 7 trillion passenger-kilometres by air.  As you might expect, a passenger-kilometre is equal to moving one person one kilometre. Therefore, if a plane carrying 100 people flies 1,000 kms that is equal to 100,000 passenger-kilometres (pkms).

The graph’s shape is significant; it reflects exponential growth: an ever-steeper upward curve. A system that grows exponentially doubles in a constant time-period. The amount of air travel we consume is doubling every 15 years. Thus, over the past 30 years, it has doubled twice, such that pkms were more than 4 times higher in 2016 than in 1986.

This exponential increase—this doubling and redoubling—is predicted to continue.  Aircraft manufacturer Airbus projects that pkms will double again by 2030 and continue upward (Global Market Forecast 2016). Forecasts by airline industry group International Air Transport Association and Boeing similarly project a doubling in coming years.

This projected doubling by 2030 is significant and troubling. In the lead-up to the 2015 Paris climate talks, nearly every nation pledged to reduce greenhouse gas (GHG) emissions. Canada committed to reducing its emissions by 30 percent by 2030. The United States made a similar commitment: a 26 to 28 percent reduction by 2025. One could sum up the world’s commitments, roughly, by saying we have a global goal of reducing emissions by 30 percent by 2030. Over that same period, however, Boeing, Airbus, and the world’s airlines will be working to increase global air travel by 100 percent. Something has to give. If the world’s airplane manufacturers, airlines, resort destinations, and tourist industry succeed in redoubling air travel, the resulting GHG emissions will contribute to massively destabilizing Earth’s climate.

To meet our targets to cut GHG emissions by 30 percent in just 13 years, and by perhaps 50 percent or more by mid-century, we must ground most of the airplanes and replace them with trains powered by electricity generated from renewable, low-emission sources. If a traveler must cross the ocean, then perhaps that person should travel in a plane. But within the North American continent, within Europe, within Asia, and wherever oceans do not present a barrier, travel will have to be transferred over to fast trains. And because these trains can go from city-centre to city-centre, because trains can travel at hundreds of kms per hour, and because train journeys do not require the lengthy security checks common at airports, door-to-door travel times in trains can be less than those in planes.

Citizens and travelers face a choice: keep the planes flying, continue to increase the amount we fly, increase road travel similarly, miss our emission targets by a mile, and destroy our chances of a stable, prosperous future; or invest in high-speed rail, create local jobs, and create a twenty-first century transportation system that aligns with our emission-reduction and sustainability goals.  We must ground most of the global airline fleet if we want to meet our emission-reduction goals.  And we must build a new system of fast trains if we want to meet our travel and quality-of-life goals.  Indeed, there is no reason that the factories and technologies currently in possession of aircraft makers Boeing, Airbus, Bombardier, Embraer, and other manufactures could not be repurposed to build those trains.

Graph sources: Airlines for America: Annual Results World Airlines

Deep into the red: US national debt per family, 1816 to 2016

US national debt graph 1816 to 2016, dollars per family
United States national debt, per family of four, 1816-2016

In the United States, federal government debt is nearly $20 trillion. That works out to about $62,000 per person, or just under $250,000 for a hypothetical family of four. Adjusted for inflation, debt has doubled since 2002, and is five times higher than in 1982.

The graph above shows the increasing size of the US national debt. The time-frame is 1816 to 2016. The units are US dollars, adjusted for inflation. In the graph, some conflict periods are highlighted in a contrasting colour. Wars have caused rapid increases in government debt. Indeed, the wars in Iraq and Afghanistan (2002-2014) played significant roles in creating the unprecedented level of debt US families now must carry. Other factors include a financial meltdown and bailout, and tax cuts that eroded revenues and forced governments to fund a greater portion of their services with borrowed money. As visible in the graph, 1982 marks the beginning of the recent phase of debt expansion. That is also the beginning of the modern era of tax cutting—the implementation of the Reagan tax cuts. US citizens have enjoyed tax cuts, but have yet to pay for them.

The graph shows that periods of increasing national debt (the Civil War, WW I, and WW II) were followed by periods of declining debt. The question now is this: Does the US economy retain enough vigour, and do US citizens and businesses retain enough good sense and discipline, to pay down $20 trillion in federal government debt, trillions more in personal debt, and trillions more in city, county, and state debts? It is never wise to bet against America. But de-industrialization, rising income inequality, world-leading incarceration rates, uncontrolled gun crime, Detroit and similar rustbelt cities, legislative gridlock, crumbling infrastructure, and a retreat into ideology all raise serious concerns.

For comparison, Canadian national debt works out to about $80,000 (Cdn.) per hypothetical family of four. Canadians, however, must not feel in any way superior or safe, because the Canadian and US economies are so tightly tied. Rising US debt is a concern for all the world’s citizens.

Graph sources: U.S. Department of the Treasury, “TreasuryDirect: Historical Debt Outstanding–Annual” 

Turning fossil fuels into fertilizer into food into us: Historic nitrogen fertilizer consumption

Graph of historic global fertilizer use, including nitrogen fertilizer, 1850-2015
Global consumption of nitrogen fertilizer and other fertilizers, historic, 1850 to 2015

Last week’s blog post (Feeding the World) showed that farmers worldwide had, since 1950, quadrupled grain production. How is this possible? The answer is fertilizer; more specifically, nitrogen fertilizer. This graph shows global fertilizer use. In 1950, farmers applied less than 5 million tonnes of nitrogen (measured in terms of actual nutrient, not fertilizer product). In 2015, farmers applied more than 110 million tonnes. We managed to increase grain output fourfold largely by increasing nitrogen inputs 23-fold.

Nitrogen fertilizer is a fossil fuel product, made primarily from natural gas. One can think of a modern nitrogen fertilizer factory as having a large natural gas pipeline feeding into one end and a large pipe coming out the other carrying ammonia, a nitrogen-rich gas. To produce, transport, and apply one tonne of nitrogen fertilizer requires an amount of energy equal to almost two tonnes of gasoline. One reason we have been able to increase grain production fourfold since 1950, and human population threefold, is that we found a way to turn fossil fuels into plant nutrients into enlarged food supplies into us. With fertilizers, we can convert hydrocarbons into carbohydrates.

Dr. Vaclav Smil is an expert on the material flows, nutrient cycles, and energy transformations that underpin natural and human systems. He believes that without the capacity to turn fossil fuels into nitrogen fertilizers into enlarged harvests, nearly half the 7.4 billion people now on Earth could not be fed and could not exist. Smil calls factory-made nitrogen “the solution to one of the key limiting factors on the growth of modern civilization.” This blog highlights the many ways humans have managed to remove the limiting factors to the growth of modern civilization.

Finally, 1950 was long ago. Surely rapid increases in fertilizer consumption must have tapered off in recent years. That isn’t the case. Canadian consumption is rising especially rapidly. A look at Statistics Canada data (CANSIM 001-0069) reveals that Canadian nitrogen fertilizer consumption has increased 65 percent over the past decade (2006 to 2016). Like many countries, Canada is boosting food output by increasing the use of energy-intensive agricultural inputs.

Graph sources: Vaclav Smil, Enriching the Earth; UN FAO, FAOSTAT; International Fertilizer Industry Association, IFADATA; and Clark Gellings and Kelly Parmenter, “Energy Efficiency in Fertilizer Production and Use.”

Feeding the world: our struggle to multiply global grain production

Graph of global grain production historic 1950 to 2016
Global grain production, annual, 1950–2016

This blog post and the next (Turning fossil fuels into … food) look at the rapid expansion of our global food supply and how we’ve accomplished that feat. The graph above shows world grain production for the past 66 years: 1950 to 2016. The units are billions of tonnes of annual production of all grains: primarily wheat, corn, rice, barley, oats, and millet. The figures exclude oilseeds, tonnage of which is about one-fifth as large as that of grains.

By utilizing ever-increasing inputs of water, machinery, fuels, chemicals, technologically-enhanced seeds, and, especially, fertilizers, the world’s farmers have managed to quadruple global grain production since 1950, and to double production since 1975. This expansion has been accomplished on a largely unchanged land area. Farmers have doubled output since the mid-’70s on a cropland area that, according to the UN’s Food and Agriculture Organization (FAO), has increased by just 5 percent.

The UN projects that global human population will increase by 50 percent by the end of this century, to 11.2 billion. That enlarged population will likely be richer, on average, than today’s population. Thus, per-capita meat demand will probably rise. When we feed grains to livestock, we turn 5 to 10 grain Calories into 1 meat Calorie. Thus, diets rich in meat require higher levels of grain production. Coming on top of these drivers of increased grain consumption is the likely increase in demand for biofuels, biomass, and feedstocks for “the bioeconomy.” The Global Harvest Initiative is an industry group whose members include John Deere, Monsanto, Mosaic, and Dupont. The group asserts that there is a “Global Agricultural Imperative” to “nearly double global agricultural output by 2050 to respond to a rapidly growing population and to meet the consumer demands of an expanding middle class.” If this doubling is accomplished, it will mark an 8-fold increase over 1950 production levels. Few citizens or policymakers are aware that the bounty in our supermarkets and on our tables depends upon very rapid and difficult-to-sustain rates of growth in food production.

Graph sources: 1960-2016: United States Department of Agriculture (USDA) World Agricultural Supply and Demand Estimates (WASDE),  ; 1950 and 1955: Lester Brown and Worldwatch Institute, various publications. Brown and Worldwatch cite USDA, “World Grain Database,” unpublished printout, 1991.

This isn’t normal: 2,000 years of economic growth

Graph of gross world product (GWP) historic, for the past two thousand years
Gross World Product (GWP) over the long term, 1 CE – 2015 CE

The graph above places our 21st century global economy in its long-term context. It plots Gross World Product (GWP), the global aggregation of Gross Domestic Product (GDP). The time frame is the past 2,015 years: 1 CE (or AD) to 2015 CE. The units are trillions of US/international dollars adjusted for inflation (converted to 1990 dollars). The main source is Angus Maddison.  Pre-20th century values are, by necessity, informed estimates by Maddison.

The year 1870 is marked with a white circle. In the millennia before 1870, the size of the global economy barely grew at all. Then, not long before the eve of the 20th century, all Hell broke loose. The most recent ten or fifteen decades appear in our historical economic record like an explosion. For perhaps 98 percent of human history, the economic trendline has been almost flat—horizontal. Over the past century-and-a-half it has been almost vertical.

The late-19th, 20th, and early 21st centuries have not been “normal.” They have been extraordinary and wondrous. Equally extraordinary is how far we have gone to normalize what is clearly an abnormal situation. Though our lifestyles and expectations are now tightly bound to near-vertical trendlines we talk and act as if nothing out of the ordinary is happening, and that we can count on more of the same for the foreseeable future.

Moreover, the 20th and 21st century exceptionalism on display in this graph is not limited to economic growth. Graphs of energy use, population, cotton or iron production, water withdrawals, food production, automobile numbers, air-travel miles, and nearly any other economic metric will look nearly identical to the graph above: millennia of little or no growth, then a sudden spike. There is upon the Earth a wholly new kind of civilization.

Graph sources: Angus Maddison, The World Economy, vol. 2, Historical Statistics (Paris: OECD, 2006) Tables 7b and 8b; and World Bank, “World DataBank: World Development Indicators: GDP at market prices” 

The Rule of 70

Graph of an exponential curve illustrating exponential growth and the Rule of 70.
16-fold exponential increase caused by a constant 2.8 percent growth rate over 100 years

This graph’s smooth curve shows how an investment, economy, population, or any other quantity will grow at a constant rate of interest or growth—that is, at a constant percentage. In this case the percentage is 2.8 percent, compounded annually.

In the graph, in year 0 the value is 1. Soon, though, the value is twice as high, rising to 2. It doubles again to 4, doubles again to 8, and again to 16. An economy or investment growing at 2.8 percent per year will double every 25 years. Thus, it will double 4 times in a century: 2, 4, 8, 16.

There is a very useful tool for quickly calculating the doubling time for a given growth rate: the Rule of 70. If you know the percentage growth rate and want to know how long it will take an initial value to double, simply divide 70 by the rate. In this case, 70 divided by 2.8 = 25. The value doubles every 25 years and therefor increases 16-fold in 100 years.

By the Rule of 70 we can calculate that a growth rate of 7 percent will cause an initial value to double in just 10 years. China’s economy has been growing by more than 7 percent since the early 1990s. If a value—the size of China’s economy, for example—doubles every 10 years, it will go through 10 doublings in a century: 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024. If China’s economy maintained a 7 percent growth rate for a century it would become more than 1,000 times larger. It is important to recall such facts the next time the Dow or some other economic indicator falls on the news that Chinese growth has “slowed” to 7 percent or less.

Exponential growth: US and Canadian GDP in the 20th century

US and Canadian Gross Domestic Product (GDP) historic
Canada and US Gross Domestic Product (GDP), 1900–2016

This graph shows the increasing sizes of the US and Canadian economies. The graph plots US Gross Domestic Product (GDP) on the left-hand axis, and Canadian GDP on the right. The time-frame is 1900 to 2016. The year 2000 is marked with an open circle, to highlight the 20th century. The units are trillions of US or Canadian dollars, and all figures are adjusted for inflation, that is, they are stated in 2016 dollars.

How much did these economies grow during the 20th century? US GDP in 1900 was $0.59 trillion dollars (in today’s US currency). In 2000, GDP was $14.3 trillion dollars—24 times larger. Canada’s economy in 2000 was 45 times larger than in 1900.

We can calculate the average annual growth rate. During the 20th century, the US economy grew at an average compound rate of 3.2 percent. We often hear growth rates of 2 to 3 percent described as normal. Indeed, if rates in the US or comparable nations fall below 2 percent, analysts warn of “slow growth.” Moreover, in recent years there has been consternation as Chinese economic growth rates have fallen from 9 or 10 percent per year to 7.

Can the US and comparable economies grow at rates in the 21st century that were “normal” in the 20th? Even if annual growth slows to an average of just 2 percent, the size of the US economy will increase 7-fold between 2000 and 2100. If the US economy grows at 2 percent per year throughout the 21st century, by 2100 the US economy alone will be more than twice as large as the global economy of 2000.

Growth rates of 2 or 3 percent per year, modest when considered over the short term, will, over several decades, cause an economy to double and redouble in size. Can we multiply the sizes of already-large national economies five- or ten-fold this century? Is it wise to try?

Graph sources: United States GDP: US Deptartment of Commerce, Bureau of Economic Analysis, NIPA Table 1.1.5; and Louis Johnston and Samuel Williamson, “What Was the U.S. GDP Then?” MeasuringWorth, https://www.measuringworth.com/usgdp/ . Canadian GDP: Statistics Canada CANSIM Tables 380-0566 and 384-0037; and M.C. Urquhart, “New Estimates of Gross National Product, Canada, 1870-1926…,” in Long-Term Factors in American Economic Growth, eds. Stanley Engerman and Robert Gallman (Chicago: University of Chicago Press, 1986)

Introduction to my blog, and to my forthcoming book

Welcome to Graphic Descriptions and my first post. Each week I will publish a new graph that will provide insights into the core processes, flows, energy sources, and transformations that underpin our immensely powerful, productive, and perilous 21st century civilization.

I’m interested in several questions, including, how did more than a billion of us come to live so well? What can history tell us about the future of our food and energy systems? Can we maintain “normal” 20th century economic growth rates through the 21st century? Is it wise to try? What can we learn from material flows within rainforests and coral reefs that will enable us to restructure our civilization so that it might be possible to keep some version of it functioning for hundreds or thousands of years into the future? How will our grandchildren heat their homes and charge their phones?

This blog is a companion to my forthcoming book. That book is complete and I hope that it can be published in 2017 or ’18. Like this blog, my book focuses on our global 21st century civilization. It explores our history, including the transformation of food and energy systems, with the aim of illuminating our future. If we do not understand how our 21st century civilization works, we can neither direct it, nor protect it.

I will post regular updates on this site regarding my book and its availability.

Welcome to Graphic Descriptions, and to a weekly exploration of the energy sources, processes, perils, and possible futures of the most powerful civilization that has ever existed on Earth.