Welcome to Australia, a land of creatures out to kill you… maybe


Ronelle Welton, University of Melbourne

Welcome to Australia, a place that is the focus of regular reports that nearly every creature is ready and waiting to pounce. If it rains, it brings warnings of venomous snakes. If the weather is dry, then giant spiders can set up house in your power box.

But as Australia prepares once again to welcome many new citizens this Australia Day, it seems appropriate to take a closer look at how deadly our creatures really are.

There is no doubt Australia harbours venomous animals and encounters that can be traumatic and need a rapid emergency response.

We must we careful not to understate the impact of any encounters with venomous animals on families and the sufferers themselves. Nor must we play down the highly specialised management, effective treatment and medical care required.

But is this reputation of a land of deadly and aggressive creatures well founded?

Detail in the data

My colleagues and I recently published a review of hospital admissions and deaths caused by venomous animals in the Internal Medical Journal.

We sourced data from 2001-2013 from national hospital admissions and national coronial information, which showed more than 42,000 hospitalisations from venomous sting or bites. Most – not all – are shown in the graph, below.

https://datawrapper.dwcdn.net/UINJU/1/

Over the 12 years that’s an average 3,500 people admitted to hospital every year for a venom-related injury. This can be loosely averaged 0.01% of the Australian population per year, or roughly one in 10,000 Australians.

Allergy or anaphylaxis from insect stings such as bees or wasps were responsible for about one-third (33%) of hospital admissions, followed by spider bites (30%) and snake bites (15%).

https://datawrapper.dwcdn.net/PJ4fJ/1/

Over the 12 years, 64 people were killed by a venomous sting or bite, with more than half of these (34) caused by an allergic reaction to an insect bite that brought on anaphylactic shock.

Of these, 27 deaths were the result of a bee or wasp sting, with only one case of a beekeeper being killed. Anaphylaxis to tick and ant bites combined caused five deaths, the box jellyfish caused three deaths and two deaths were from an unidentified insect.

Given there are 140 species of land snakes in Australia, snake bite fatalities are very rare, at 27 for the study period. To put that in perspective, the World Health Organization estimates that at least 100,000 people die from snake bite globally each year.

The red belly black snake is not as nasty as it looks.
Flickr/Derek A Young, CC BY-NC

While it’s natural to be frightened of snakes, the reality is the number of deaths from snake bites in Australia is very small. In the same time frame, for example, figures from the National Coronial Information System (NCIS) show nearly 5,000 people died from drowning and 1,000 from burns in Australia.

Nevertheless, snake bites do hold the crown as the most common cause of death, with nearly twice as many deaths per hospital admission than any other venomous injury, making snakebite one of the most important issues to address.

Deadly creatures elsewhere

Understandably, living in a country with creatures that can potentially kill us is a daunting prospect. As you can see from the figures, though, they don’t kill as many people as you might think and other countries have their own potentially deadly creatures.

In the United Kingdom there are reports of deaths or injuries from bees, widow spiders, jellyfish and adder snakes.

The continent of America has a menagerie of reptilian assassins such as vipers, and its mammals also pack a punch, with reports of attacks from bears, wolves and mountain lions.

A sturdy Australian would surely quake at the thought of being faced with an offensive grizzly, with no amount of Crocodile Dundee-esk buffalo hypnotism techniques going to get us through that encounter.

Sure Australia also has sharks and crocodiles, but it’s important to note that the majority of our critters do not come after you.

Minimising the minimal risk

Our report, while giving a broad overview of envenoming trends in Australia, does raise more questions than it answers. Questions such as: who is most at risk and how can we support them? Do we need more localised guidelines? And how do we maintain knowledge for such a rare injury?

No one died from a spider bite during the 12 years of our study.
Flickr/Corrie Barklimore, CC BY

This work seeks to initiate new conversations in regard to potential gaps in knowledge in both the public and health domains, and find solutions. We’re currently seeking funding to continue this research.

From an individual or national public health perspective, we can’t make informed decisions until we have a much clearer picture of what’s going on. The big question is how can we manage this coexistence with the creatures around us, without being detrimental to people and the creatures themselves.

It comes down to understanding, appreciating and respecting the amazing diversity nature has provided us. We need to learn about prevention methods and understand correct first aid.

This, together with the ongoing research and improvements in clinical care and the accessibility, affordability, effective management and treatment of bites and stings in Australia, actually make it one of the safest places in the world, and certainly not one of the deadliest.

The Conversation

Ronelle Welton, Scientist at the Australian Venom Research Unit, University of Melbourne

This article was originally published on The Conversation. Read the original article.

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Current emissions could already warm world to dangerous levels: study


Andrew Glikson, Australian National University

Current greenhouse gas concentrations could warm the world 3-7℃ (and on average 5℃) over coming millennia. That’s the finding of a paper published in Nature today.

The research, by Carolyn Snyder, reconstructed temperatures over the past 2 million years. By investigating the link between carbon dioxide and temperature in the past, Snyder made new projections for the future.

The Paris climate agreement seeks to limit warming to a “safe” level of well below 2℃ and aim for 1.5℃ by 2100. The new research shows that even if we stop emissions now, we’ll likely surpass this threshold in the long term, with major consequences for the planet.

What is climate sensitivity?

How much the planet will warm depends on how temperature responds to greenhouse gas concentrations. This is known as “climate sensitivity”, which is defined as the warming that would eventually result (over centuries to thousands of years) from a doubling of CO₂ concentrations in the atmosphere.

The measure of climate sensitivity used by the Intergovernmental Panel on Climate Change (IPCC) estimates that a doubling of CO₂ will lead to 1.5-4.5℃ warming. A doubling of CO₂ levels from before the Industrial Revolution (280 parts per million) to 560ppm would likely surpass the stability threshold for the Antarctic ice sheet.

As the world warms, it triggers changes in other systems, which in turn cause the world to warm further. These are known as “amplifying feedbacks”. Some are fast, such as changes in water vapour, clouds, aerosols and sea ice.

Others are slower. Melting of the large ice sheets, changes in the distribution of forests, plants and ecosystems, and methane release from soils, tundra or ocean sediments may begin to come into play on time scales of centuries or less.

Other research has shown that during the mid-Pliocene epoch (about 4.5 million years ago) atmospheric CO₂ levels of about 365-415ppm were associated with temperatures about 3–4 °C warmer than before the Industrial Revolution. This suggests that the climate is more sensitive than we thought.

This is concerning because since the 18th century CO₂ levels have risen from around 280ppm to 402ppm in April this year. The levels are currently rising at around 3ppm each year, a rate unprecedented in 55 million years. This could lead to extreme warming over the coming millennia.

Temperature histories from paleoclimate data (green line) compared to the history based on modern instruments (blue line) suggest that global temperature is warmer now than it has been in the past 1,000 years, and possibly longer.
NASA, Author provided

More sensitive than we thought

The new paper recalculates this sensitivity again – and unfortunately the results aren’t in our favour. The study suggests that stabilisation of today’s CO₂ levels would still result in 3-7℃ warming, whereas doubling of CO₂ will lead to 7-13℃ warming over millennia.

The research uses proxy measurements for temperature (such as oxygen isotopes and magnesium-calcium ratios from plankton) and for CO₂ levels, calculated for every 1,000 years back to 2 million years ago.

Some other major findings include:

The Earth cooled gradually to about 1.2 million years ago, followed by an increase in the size of ice sheets around 0.9 million years ago, and then followed by around 100,000-year-long glacial cycles.

Over the last 800,000 years, and particularly during glacial cycles, atmospheric greenhouse gas concentrations and global temperature were closely linked.

The study shows that for every 1℃ of global average warming, Antarctica warms by 1.6℃.

So what does all this mean for the future?

Global warming past and future, triggered initially by either changes in solar radiation or by greenhouse gas emissions, is driven mainly by amplifying feedbacks such as warming oceans, melting ice, drying vegetation in parts of the continents, fires and methane release.

Current CO₂ levels of around 400ppm, combined with methane (rising toward 1,900 parts per billion) and nitric oxide (around 310ppb), are already driving such feedbacks.

According to the new paper, such greenhouse gas levels are committing the Earth to extreme rises of temperature over thousands of years, with consequences consistent with the large mass extinctions.

The IPCC suggests warming will increase steadily as greenhouse gases increase. But the past shows there will likely be abrupt shifts, local reversals and tipping points.

Abrupt freezing events, known as “stadials”, follow peak temperatures in the historical record. These are thought to be related to the Mid-Atlantic Ocean Current. We’re already seeing marked cooling of ocean regions south of Greenland, which may herald collapse of the North Atlantic Current.

A global temperature map for 2015 showing the cold water region in the North Atlantic Ocean.
NASA, Author provided

As yet we don’t know the details of how different parts of the Earth will respond to increasing greenhouse gases through both long-term warming and short-term regional or local reversals (stadials).

Unless humanity develops methods for drawing down atmospheric CO₂ on a scale required to cool the Earth to below 1.5°C above pre-industrial temperature, at the current rate of CO₂ increase of 3ppm per year we are entering dangerous uncharted climate territory.

The Conversation

Andrew Glikson, Earth and paleo-climate scientist, Australian National University

This article was originally published on The Conversation. Read the original article.

Australia’s 10 Most Dangerous Animals


The link below is to an article that lists the ’10 most dangerous animals in Australia.’ However, you may find some of these animals not quite as dangerous as the author of this article would have you believe.

For more visit:
http://mashable.com/2015/08/06/australia-most-dangerous-animals/

Dangerous global warming could be reversed, say scientists


Grist

Global warming could be reversed using a combination of burning trees and crops for energy, and capturing and storing carbon dioxide underground (CCS), according to an analysis by scientists. But experts cautioned that trying such an approach after temperatures had passed dangerous levels could be problematic, as climate change reduced the number of trees available for “bioenergy.”

The bioenergy and CCS method was the most cost-effective way of tackling carbon emissions, said the team at Chalmers University of Technology in Sweden, publishing their research in the journal Environmental Research Letters on Thursday. Such an approach could offset and even reverse other emissions from fossil fuels, they claimed.

The lead author of the study, Christian Azar, said it could help bring temperatures down even if they rose above the 2 degrees C level that world leaders have agreed to avoid: “Even if current political gridlock causes…

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