Cartoon guide to biodiversity loss XXX 30

27 05 2015

[10.06.2015 update: Because of all the people looking for cartoon porn, I’ve slightly altered the title of this post. Should have predicted that one]

Third batch of six biodiversity cartoons for 2015 (see full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here).

Read the rest of this entry »





Statistical explainer: average temperature increases can be deceiving

12 05 2015

Beating-the-Heat-Without-PowerOver the years I’ve used a simple graphic from the IPCC 2007 Report to explain to people without a strong background in statistics just why average temperature increases can be deceiving. If you’re not well-versed in probability theory (i.e., most people), it’s perhaps understandable why so few of us appear to be up-in-arms about climate change. I posit that if people had a better appreciation of mathematics, there would be far less inertia in dealing with the problem.

Instead of using the same image, I’ve done up a few basic graphs that explain the concept of why average increases in temperature can be deceiving; in other words, I explain why focussing on the ‘average’ projected increases will not enable you to appreciate the most dangerous aspects of a disrupted climate – the frequency of extreme events. Please forgive me if you find this little explainer too basic – if you have a modicum of probability theory tucked away in your educational past, then this will be of little insight. However, you may wish to use these graphs to explain the problem to others who are less up-to-speed than you.

Let’s take, for example, all the maximum daily temperature data from a single location compiled over the last 100 years. We’ll assume for the moment that there has been no upward trend in the data over this time. If you plot the frequency of these temperatures in, say, 2-degree bins over those 100 years, you might get something like this:

ClimateVarFig0.1

This is simply an illustration, but here the long-term annual average temperature is 25 degrees Celsius, and the standard deviation is 5 degrees. In other words, over those 100 years, the average daily maximum temperature is 25 degrees, but there were a few days when the maximum was < 10 degrees, and a few others where it was > 40 degrees. This could represent a lot of different places in the world.

We can now fit what’s known as a ‘probability density function’ to this histogram to obtain a curve of expected probability of any temperature within that range:

ClimateVarFig0.2

If you’ve got some background in statistics, then you’ll know that this is simply a normal (Gaussian) distribution. With this density function, we can now calculate the probability of any particular day’s maximum temperature being above or below any particular threshold we choose. In the case of the mean (25 degrees), we know that exactly half (p = 0.50) of the days will have a maximum temperature below it, and exactly half above it. In other words, this is simply the area under the density function itself (the total area under the entire curve = 1). Read the rest of this entry »





Missing the forest despite its trees

21 04 2015

An exchange on Alert-Conservation.org over the intactness of boreal forests has just erupted. Bill Laurance asked me to weigh in as an independent appraiser of the debate, so I copy my thoughts below. You can read the original exchange between Jeff Wells and Nick Haddad (& colleagues) here.

Despite its immense size, there is little doubt that the ugly second cousin of forest conservation is the boreal region covering much of Alaska, Canada, Fennoscandia and Russia. Indeed, extending some 1.4 billion hectares, of which well over 60% is found in Russia alone (1, 2), the entirety of the boreal forest is more than double the area of the Amazon forest. Yet despite this massive expanse, the impressive biota it shelters (2), and its important contribution to the global carbon (1), nitrogen (3) and oxygen (4) cycles, the boreal is an oft-overlooked region in terms of global conservation priorities and possibilities (5).

The exchange between Haddad & Sexton and Wells regarding the former researchers’ recent paper (6) highlights this problem, of which even many expert ecologists are often only vaguely aware. Wells takes particular issue with Haddad and colleagues’ assertion that the boreal forest is highly fragmented, claiming to the contrary that the (North America) boreal forest is “… truly intact … ”. While Haddad et al. respond that they did not differentiate between ‘natural’ and human-caused fragmentation, my view is that the exchange misses some important concerns about the state of the boreal forest.

Wells correctly points out that the boreal zone in North America is “massive”, but can his other claim – that it is “truly intact” – stand up to scrutiny? Citing one of my own papers from 2009 (2) to demonstrate (correctly) that the boreal forest of North America holds a stunning array of species, Wells neglects to highlight that in that same paper we also identified the extensive, artificial fragmentation that has occurred there and in other parts of the boreal zone over the last few decades. For example, we showed clearly that only 44% of the entire biome is considered to be ‘intact’, defining the term precisely as “areas ≥ 500 km2, internally undivided by infrastructure (e.g., roads) and with linear dimensions ≥ 10 km”. Satellite imagery has also confirmed that between 2000 and 2005, the boreal biome experienced the largest area of gross forest cover loss compared to any other (7). Despite recent evidence that so-called edge effects (characteristics of a disturbed matrix that penetrate some distance into habitat fragments) are probably of a smaller spatial magnitude in boreal compared to other biomes (8), it is disingenuous to claim that North America’s boreal forests are “truly intact”. Read the rest of this entry »





How things have (not) changed

13 04 2015

The other night I had the pleasure of dining with the former Australian Democrats leader and senator, Dr John Coulter, at the home of Dr Paul Willis (Director of the Royal Institution of Australia). It was an enlightening evening.

While we discussed many things, the 84 year-old Dr Coulter showed me a rather amazing advert that he and several hundred other scientists, technologists and economists constructed to alert the leaders of Australia that it was heading down the wrong path. It was amazing for three reasons: (i) it was written in 1971, (ii) it was published in The Australian, and (iii) it could have, with a few modifications, been written for today’s Australia.

If you’re an Australian and have even a modicum of environmental understanding, you’ll know that The Australian is a Murdochian rag infamous for its war on science and reason. Even I have had a run-in with its outdated, consumerist and blinkered editorial board. You certainly wouldn’t find an article like Dr Coulter’s in today’s Australian.

More importantly, this 44 year-old article has a lot today that is still relevant. While the language is a little outdated (and sexist), the grammar could use a few updates, and there are some predictions that clearly never came true, it’s telling that scientists and others have been worrying about the same things for quite some time.

In reading the article (reproduced below), one could challenge the authors for being naïve about how society can survive and even prosper despite a declining ecological life-support system. As I once queried Paul Ehrlich about some of his particularly doomerist predictions from over 50 years ago, he politely pointed out that much of what he predicted did, in fact, come true. There are over 1 billion people today that are starving, and another billion or so that are malnourished; combined, this is greater than the entire world population when Paul was born.

So while we might have delayed the crises, we certainly haven’t averted them. Technology does potentially play a positive role, but it can also increase our short-term carrying capacity and buffer the system against shocks. We then tend to ignore the indirect causes of failures like wars, famines and political instability because we do not recognise the real drivers: resource scarcity and ecosystem malfunction.

Australia has yet to learn its lesson.

To Those Who Shape Australia’s Destiny

We believe that western technological society has ignored two vital facts: Read the rest of this entry »





Cartoon guide to biodiversity loss XXIX

9 04 2015

Second batch of six biodiversity cartoons for 2015 (see full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here).

Read the rest of this entry »





Australians: out-of-touch, urban squanderers

23 03 2015

There’s a romantic myth surrounding Australia that is pervasive both overseas and within the national psyche: this sun-scorched continent home to stoic bushmen1 that eek out a frugal, yet satisfying existence in this harsh rural land. Unfortunately that ideal is anathema to almost every Australian alive today.

While some elements of that myth do have a basis in reality – it is indeed a hot, dry, mostly inhospitable place if you count the entire land area (all 7.69 million square kilometres of it), and it does have the dubious honour of being the driest inhabited continent on Earth – most Australians live nowhere near the dry interior or the bush.

Despite our remarkably low average population density (a mere 3.09 people per square kilometre), Australia is in fact one of the most urbanised nations on the planet, with nearly 90% of its citizenry living within a major urban centre. As a result, our largely urban/suburban, latte-sipping, supermarket-shopping population has little, if any, connection to the vast landscape that surrounds its comfortable, built-up environs. There should be little wonder then that Australians are so disconnected from their own ecology, and little surprise that our elected officials (who, after all, represent the values of the majority of the citizens they purport to represent), are doing nothing to slow the rapid flushing of our environment down the toilet. Indeed, the current government is in fact actively encouraging the pace of that destruction. Read the rest of this entry »





Australia’s perfect storm of negligence

17 03 2015

If, for the purposes of some sick and twisted thought experiment, you were to design policies that would ensure the long-term failure of a wealthy, developed nation, you wouldn’t have to look farther than Australia’s current recipe for future disaster. I’m not trying to be provocative, but the warning signs are too bold and flashy to ignore. Let’s just run through some of the main ones:

1. As the lambasted and thoroughly flawed 2015 Intergenerational Report clearly demonstrates, our current government has no idea about the future threats of climate change. Dragged kicking and screaming into only a symbolic recognition of some ‘distant and currently irrelevant problem’, the Abbott-oir and his intergenerational criminals are well known for killing the carbon-pricing scheme, dismantling the Department of Climate Change, pulling out of major international talks on climate-change mitigation and installing a half-arsed, ineffective policy that will do nothing to stem our emissions. Combine that with comments like “coal is good for humanity“, and it’s easy to see how our current leaders have little idea about the future mess they’re creating.

2. Not content just to kick the shit out of any meaningful climate action, our government has also turned its back on any renewable energy target, and facilitated the fossil-fuel barons to dig more coal out of the ground. While South Australia’s Royal Commission on the nuclear fuel cycle is a welcome candle in the climate change-mitigation darkness here, it is far from becoming a national priority any time soon.

3. As has been well documented, the Abbott-oir ship of fools has also done whatever it can to turn back decades of environmental protections in less than six months of taking office. Everything from opening up national parks for exploitation, failing to protect marine sanctuaries, limiting environmental checks to promoting logging in World Heritage Areas, there is little room for hope that our crumbling environmental system will improve at all in the near to long term. Read the rest of this entry »








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