Religion and babies: are believers to blame for overpopulation?

In the context of rising global population (see my more detailed comments here), what effect does religious affiliation have on fertility?

Hans Rosling is one of the key figures behind the fascinating work at GapMinder, which aims to bring global statistics to life for ordinary people. He is something of a regular at TED and his talks are always entertaining and interesting. I have posted a few before.

Warning: the method he uses is applicable only at the broadest (national) level and so flattens some interesting exceptions, but other more detailed studies do support his basic claim here.

So long and thanks for all the fish

I recently came across this summary of the state of the world's marine life after decades of industrial scale pollution, warming, acidification, trawling, nutrient runoff and overfishing. It is from this paper.

Our ecological crises: Wake up and smell the stats

I'd like to put together a list of credible ecological statistics from reputable sources as a resource. Please post links to any such existing lists you are aware of or add any that have grabbed your attention (please make sure you include a source). To start us off, here are a few off the top of my head and in no particular order:

• Humans now affect over 80% of the world's land, 100% of the oceans and 100% of the atmosphere. Around 40% of the oceans have been "strongly affected" by our activities.

• Half of the world’s tropical forests have disappeared since World War II and roughly another 10 million hectares are being felled each year — the equivalent of 40 football fields every minute. The majority are being cleared by illegal loggers.

• Seventy-seven percent of global fisheries are fully exploited, over exploited or have been depleted. Based on 1998 data, the UN Food and Agriculture Organization estimates that global fishing fleets "are 2.5 times larger than needed."

• Marine apex predator numbers (i.e. large fish and sharks) have declined by 90% over the last 50-100 years, mainly due to overfishing (more stats on marine life decline). Another recent study put tuna decline at 60% in the last 50 years.

• Deep-sea trawling damages an area of sea bed twice the size of the contiguous USA each year.

• We're removing 9-10,000 tonnes of fish from the ocean every hour.

• As far as we can work out (and there are wide error margins on this one), species are currently going extinct at something like 100-1000 times the background rate of extinction, faster than at any time since the extinction of the dinosaurs 65 million years ago. It is likely that somewhere between 5,000 and 30,000 species become extinct each year. All the primary drivers of these trends are linked to human activities: land use changes, habitat destruction, pollutants, invasive species, anthropogenic climate change.

• Twenty-two percent of the world's plant species are threatened, and another 33% have an unknown status.

• Twenty-two species of Australian mammals become extinct between 1900 and 1960. Recently, mammal populations in Kakadu have gone into freefall.

• In the 1950s there were 450,000 lions worldwide and now there are only 20,000. Leopards are down from 700,000 to 50,000, cheetahs from 45,000 to 12,000 and tigers from 50,000 to just 3,000. And in the last forty years, elephant numbers have halved across protected areas in West and Central Africa. Globally, since 1970, wild vertebrate numbers have declined by almost one third.

• One study in 2001 put the annual cost of alien invasive species to the global economy at US$1.4 trillion annually, or about 5% of total GDP.

• Overall, current ecological damage is estimated to cost the global economy US$6.6 trillion annually (yes, with a "t").

• An area of arable land roughly the size of Greece or Nepal is lost to soil erosion and desertification each year. Since 1950, 1.9 billion hectares (4.7 billion acres) of land around the world has become degraded.

• By 1995, humans consumed 20% of global net terrestrial primary production. By 2005, it was 25%.

• Earth overshoot day occurs earlier each year. This is a notional measure designating the point in the year where global consumption exceeds the annual renewable biocapacity of the planet. In 2011, it falls on 27th September. Another way of saying this is that in 2010 the worldwide human population used about 135% of the resources the earth can generate in a year.

• Between 2000 and 2010, the number of cars and motorcycles in China increased twentyfold and there are now between 800 million and one billion cars in the world.

• As we burn 196,442 kilos of coal, 103,881,279 litres of natural gas and 150,179 litres of oil a second, we're dumping 62,500 tonnes of heat-trapping emissions into the earth's atmosphere every minute. Since the industrial revolution, we have increased the carbon dioxide in the atmosphere by more than 40% and increased the acidity of the oceans by 30% (a rate faster than anything seen before in Earth's history). The radiative forcing of the carbon dioxide human activities have put in the atmosphere is the equivalent of adding the energy of more than ten Hiroshima bombs every second and is likely the most significant contributing factor in Greenland losing around 9000 tonnes of ice every second (and accelerating), in about 90% of glaciers globally retreating, in precipitating the largest marine migration in two million years due to warming oceans and in ensuring that the last 318 consecutive months have had a global temperature above the 20th century average. The last month with below average temperatures was February 1985.

• Arctic summer sea ice has declined by 40% in extent and more than 75% in volume over the last three decades and 2011 saw new records for lowest extent and volume since records began. Due to increased summer melt, the fabled North West passage through the remote islands of Canada has been open to commercial shipping without icebreakers only four times in recorded history: 2011, 2010, 2008, 2007.

• Nearly 5.5 billion people (about 80% of global human population) live in an area where rivers are seriously threatened.

• The rate at which we are extracting groundwater has more than doubled between 1960 and 2000 and since 1960 18 trillion tonnes of water have been removed from underground aquifers without being replaced, enough to raise global sea levels by an average of 5 cm.

• In 1960, the Aral Sea was the world's fourth largest lake yet by 2000 it had shrunk to 20% of its original size due to over-irrigation on its feeder rivers.

• We put more than six million tonnes of plastic in the oceans annually, which is something like eight million pieces of litter each day, and over 119,000 items floating on every square kilometre of ocean.

• It is likely humanity has had a greater effect on the nitrogen cycle than any other phenomenon for the last 2.5 billion years.

Note that none of these are projections of present trends, they all relate simply to our present condition. This is currently an unsystematic sample; I have not (yet) tried to cover all of the various ecological and resource crises. This post may grow as I continue to gather more information.
I also posted some further statistics back here, though have not had a chance to post links to all the sources of those, and their credibility is something of a mixed bag.

Where is the anger? Where is the grief? Missing feelings

Chris Jordan makes artworks of shocking statistics. His goal is to elicit anger and grief as healthy responses to the realities of western (especially US) consumerism and its contradictions, poisons and victims ("those who inherit the results of our decisions"). He fears that these responses have gone missing from our culture. He is trying to translate deadly statistics into a language that can be felt in order to open a space for reflection and change.

If you don't feel sick in the pit of your stomach during this video, either (a) he's failed or (b) you're numb (or (c) you haven't recently eaten something questionable, which may be the case with me).

Taking cars off the road

In measuring the impact of various carbon reduction strategies, communicators often reach for expressing the scale of the effort by saying that it is "the equivalent of taking x cars off the road". Using statistics like this, that bring large measurements down into a humanly comprehensible scale, is generally a good thing when trying to communicate incomprehensible figures, such as tonnes of a gas not being emitted.

However, it does make me think: why don't we also actually take cars off the road? Road transport is a major contributor to greenhouse gas emissions (far from the only or even the largest, but it is a significant sector, accounting for around 10-20% of all emissions, depending how you cut the cake). Of course, there are many strategies already aiming at reducing the carbon tyreprint: public transport, cycling lanes, user-pays road tolls, congestion charges, pedestrian-friendly new urbanism, public bicycle sharing systems, improving fuel efficiency standards, car share networks, car pooling websites, electric vehicles, improving intercity rail connections and more.

So, why then, is the "greenest government ever" announcing an end to the "war on motorists"? What does this mean? For a start, it means the removal of various restrictions on parking and other disincentives to driving, as well as a significant lift in the cap on the rate at which rail prices can rise. And it is not as though there was much a war to begin with, except perhaps for rising petrol prices due (amongst other things) to the apparent peaking of conventional oil production. As Jeremy point outs, "the best thing the government could do for motorists is promote buses and trains", since fewer cars means less traffic. As a recent billboard advertisement memorably put it: "You are not stuck in traffic. You are traffic."

Driving cars (particularly in cities) seems to be another example of thinking "red", seeking short-term personal gain that leads to everyone losing.

Fortunately, in addition to the policy measures listed above, there is something even more effective we can do to ensure we're not stuck in traffic on a warming world. We can choose to drive less, to make fewer trips, to share journeys with others, to live closer to where we want to go (and to make the places we want to go closer to where we live), to renounce desires to go long distances on a whim, to joyfully embrace less.

Chinese and US carbon emissions: myths and morality

Statistics and spin

"China is inappropriately made a scapegoat in this case because what causes the climate change is not today's emissions, it's today's atmospheric composition and we [USA] are primarily responsible for the excess carbon dioxide in the atmosphere - more than three times more than China and actually on a per capita basis more than an order of magnitude [i.e. ten times]. So to blame China and to say that we have to wait for them is nonsense."

- James Hansen, head of NASA Goddard Institute for Space Studies, in this interview.

Statistics can frequently be misleading. And so it really matters which statistics are given the most attention. It is true that China is currently the country that emits the most carbon dioxide each year. Yet Hansen is right to point out the massive historical and per capita disparity between the west and China (and India, of course). The climate change we are currently experiencing and the same again (more or less) already "in the pipeline" are due to emissions so far (there is a lag between the addition of greenhouse gases to the atmosphere and rising atmospheric temperatures as most of the energy initially goes into the oceans). And the carbon dioxide currently in the atmosphere is due very largely to the US, Germany and the UK (in that order).

Since cumulative emissions are more important than the current rate of emissions (due to the long period of time that about half the carbon dioxide we release stays in the atmosphere), then focussing simply on current rates without considering the cumulative totals obscures the bigger picture. And comparing countries with widely disparate populations also assumes that the only relevant moral unit is the nation state, a very odd assumption for individualists in the US to perpetuate. It makes much more sense to speak primarily in per capita terms. When these considerations are included, as Hansen points out, the US has little moral authority to consider China the largest contributor to the problem. Indeed, a further factor worth pondering is that roughly one-third of all China's emissions result from producing goods for western markets, so if we look at the consumption levels driving the dangerous emissions, then once again the west has little right to place the lion's share of blame for today's situation on China.

However, future emissions are also relevant, since (simplifying quite a bit), it is really the total amount of carbon dioxide humans release that matters. If we're to stay below 450 ppm (which has been the rough goal accepted by most governments - whether 450 is already too dangerous is a discussion for another day), then we've already spent more than half the carbon budget. Pre-industrial levels were around 280 ppm and we're currently at 390 ppm and rising (since more carbon dioxide is entering the atmosphere than leaving it). If this is accepted as a reasonable goal, then even if the US entirely stopped all carbon emissions tomorrow (impossible, but this is a thought experiment), China would never be able to emit as much carbon dioxide per capita as the US already has.

Does this mean that China (and other rapidly industrialising nations) bear no responsibility for their current (and rapidly rising) emissions? Of course not, but it is clear that the developed world has contributed far more to the problem than the developing world and so rightly ought to bear most responsibility for addressing it. Simply looking at current emissions obscures morally relevant considerations and enables the world's richer nations to downplay the role we have played in causing the mess. Unfortunately, such arguments are not widely understood or accepted in industrialised countries.

If you would like to see some of these statistics visualised, then Gapminder is an excellent resource. If you follow this link and click "play", you'll see a historical progression of various nations' contributions. The size of the circle indicates population size. The x-axis is per capita emissions and the y-axis is cumulative emissions. Colours are for region. You can play around with all the settings to see all kinds of relationships (a two minute tutorial is here). I haven't managed to find any graphs that compare per capita cumulative emissions. Doing so would demonstrate that China and the US are not simply in different ball parks but are playing entirely different games.