Attack of the alien invaders: pest plants and animals leave a frightening $1.7 trillion bill

19 04 2021


They’re one of the most damaging environmental forces on Earth. They’ve colonised pretty much every place humans have set foot on the planet. Yet you might not even know they exist.

We’re talking about alien species. Not little green extraterrestrials, but invasive plants and animals not native to an ecosystem and which become pests. They might be plants from South America, starfish from Africa, insects from Europe or birds from Asia.

These species can threaten the health of plants and animals, including humans. And they cause huge economic harm. Our research, recently published in the journal Nature, puts a figure on that damage. We found that globally, invasive species cost US$1.3 trillion (A$1.7 trillion) in money lost or spent between 1970 and 2017.

The cost is increasing exponentially over time. And troublingly, most of the cost relates to the damage and losses invasive species cause. Meanwhile, far cheaper control and prevention measures are often ignored.

Yellow crazy ants attacking a gecko
Yellow crazy ants, such as these attacking a gecko, are among thousands of invasive species causing ecological and economic havoc. Dinakarr, CC0, Wikimedia Commons

An expansive toll

Invasive species have been invading foreign territories for centuries. They hail from habitats as diverse as tropical forests, dry savannas, temperate lakes and cold oceans.

They arrived because we brought them — as pets, ornamental plants or as stowaways on our holidays or via commercial trade.

Read the rest of this entry »

Worried about Earth’s future? Well, the outlook is worse than even scientists can grasp

14 01 2021

Daniel Mariuz/AAP

Corey J. A. Bradshaw, Flinders University; Daniel T. Blumstein, University of California, Los Angeles, and Paul Ehrlich, Stanford University

Anyone with even a passing interest in the global environment knows all is not well. But just how bad is the situation? Our new paper shows the outlook for life on Earth is more dire than is generally understood.

The research published today reviews more than 150 studies to produce a stark summary of the state of the natural world. We outline the likely future trends in biodiversity decline, mass extinction, climate disruption and planetary toxification. We clarify the gravity of the human predicament and provide a timely snapshot of the crises that must be addressed now.

The problems, all tied to human consumption and population growth, will almost certainly worsen over coming decades. The damage will be felt for centuries and threatens the survival of all species, including our own.

Our paper was authored by 17 leading scientists, including those from Flinders University, Stanford University and the University of California, Los Angeles. Our message might not be popular, and indeed is frightening. But scientists must be candid and accurate if humanity is to understand the enormity of the challenges we face.

Girl in breathing mask attached ot plant in container

Humanity must come to terms with the future we and future generations face. Shutterstock

Getting to grips with the problem

First, we reviewed the extent to which experts grasp the scale of the threats to the biosphere and its lifeforms, including humanity. Alarmingly, the research shows future environmental conditions will be far more dangerous than experts currently believe. Read the rest of this entry »

Resolving the Environmentalist’s Paradox

7 04 2011

Here’s an extremely thought-provoking guest post by Megan Evans, Research Assistant at the University of Queensland in Kerrie Wilson‘s lab. Megan did her Honours degree with Hugh Possingham and Kerrie, and has already published heaps from that and other work. I met Megan first in 2009 and have been extremely impressed with her insights, broad range of interests and knowledge, and her finely honed grasp of social media in science. Smarter than your average PhD student, without a doubt (and she has even done one yet). Take it away, Megan.

© T. Toles

Resolving the ‘Environmentalist’s Paradox’, and the role of ecologists in advancing economic thinking

Aldo Leopold famously described the curse of an ecological education as “to be the doctor who sees the marks of death in a community that believes itself well and does not want to be told otherwise”. Ecologists do have a tendency for making dire warnings for the future, but for anyone concerned about the myriad of problems currently facing the Earth – climate change, an ongoing wave of species extinctions and impending peak oil, phosphate, water , (everything?) crises – the continued ignorance or ridicule of such warnings can be a frustrating experience. Environmental degradation and ecological overshoot isn’t just about losing cute plants and animals, given the widespread acceptance that long-term human well-being ultimately rests on the ability for the Earth to supply us with ecosystem services.

In light of this doom and gloom, things were shaken up a bit late last year when an article1 published in Bioscience pointed out that in spite of declines in the majority of ecosystem services considered essential to human well-being by The Millenium Ecosystem Assessment (MA), aggregate human well-being (as measured by the Human Development Index) has risen continuously over the last 50 years. Ciara Raudsepp-Hearne and the co-authors of the study suggested that these conflicting trends presented an ‘environmentalist’s paradox’ of sorts – do we really depend on nature to the extent that ecologists have led everyone to believe? Read the rest of this entry »

Unbounded economic growth destroying biodiversity

16 08 2010

…we can’t have more of everything instantaneously

…increasing takeover of the ecosystem is the necessary consequence of the physical growth of the macroeconomy

…consider telling the economist to go to hell

Herman Daly

© M. Leunig

Last month I had the privilege of listening to Rob Dietz of the Centre for Advancement of the Steady State Economy (CASSE) when attending the 2010 International Congress for Conservation Biology. He introduced the CASSE and their mandate – to promote stable or mildly fluctuating levels in population and consumption of energy and materials. This is the steady-state economy.

I’ve hinted before that our essentially linear economy (natural resource exploitation -> transport -> manufacturer -> redistribution -> sale -> consumption/use -> disposal (discussed in a very easy-to-understand way in the Story of Stuff) is not sustainable in the long term because of the finite resource base of the planet (think trees, coal, oil, arable land). My colleagues and I have even shown analyses based on hard data demonstrating that total wealth is the ultimate driver of environmental degradation at the country scale.

So, it is my opinion (and a growing number of others‘) that we need a new way of measuring economic prosperity, or the world will enter a state of permanent financial crisis. The mantra of constant economic growth is simply unrealistic as our human populations continue to expand. This is a very simplistic statement and on the surface an apparently impossible goal; however, people who put together the CASSE believe it is achievable.

It is for this reason that I have been communicating with Rob Dietz and others at CASSE about reposting some of their excellent essays on Please feel free to comment here on the subject matter because the CASSE people will be monitoring. I hope we can expand the readership and support base, and eventually start to convince politicians that growth will eventually kill us and a good slice of the planet’s biodiversity.

So with that, here’s the first repost by Professor Herman Daly entitled “Opportunity Cost of Growth“: Read the rest of this entry »