Methane, Climate Change, and Our Uncertain Future

The greenhouse gas, methane, is produced by both natural processes and human activities. While there has been much attention paid to curbing anthropogenic emissions, a changing climate will likely increase the production of natural methane. In an open access article recently published in Reviews of Geophysics, Dean et al. [2018] describe the ways in which biological, geochemical, and physical systems influence methane concentrations and explore how methane levels in natural systems may alter in a warming climate. Here the authors answer some questions about the sources and significance of methane, and indicate some future research directions.

Flooded permafrost tundra in northeast Siberia.
Hydrology is a key control on methane emissions
in wetland and permafrost ecosystems.
Credit: Joshua Dean

How does methane effect the Earth’s climate?

Methane (CH4) is a greenhouse gas that is much stronger than carbon dioxide (CO2), 34 times stronger if compared over a 100-year period. While concentrations of methane in the atmosphere are about 200 times lower than carbon dioxide, methane was responsible for 60% of the equivalent radiative forcing caused by carbon dioxide since the onset of the Industrial Revolution. Methane’s presence in the atmosphere can also affect the abundance of other greenhouse gases, such as ozone (O3), water vapor (H2O), and carbon dioxide.

Read the story from Earth and Space Science News by Joshua Dean - “Methane, Climate Change, and Our Uncertain Future.”

A third of world's nature reserves severely degraded by human activity

A third of global protected areas such as national parks have been severely degraded by human activities in what researchers say is a stunning reality check of efforts by nations to stall biodiversity loss.

The report’s authors said one of the most glaring examples of
human encroachment on protected areas was Barrow Island
off Western Australia, pictured, where a gas plant was built
 is in the middle of a nature reserve home to 13 mammal species. 

A University of Queensland-led study, published on Friday in the prestigious academic journal Science, analysed human activity across 50,000 protected areas worldwide.

Researchers found more than 90% of conservation sites, such as national parks and nature reserves, showed some signs of degradation from human activities including logging, mining, tourism and urbanisation and a third – or 6m square kilometres of protected land – had been severely modified.

The worst damage was found in highly populated parts of Europe, Asia and Africa, but researchers said there was significant degradation in all nations, including wealthy and less-populated countries such as Australia.

Read the story by Lisa Cox from The Guardian - “A third of world's nature reserves severely degraded by human activity.”

Only green growth can bring prosperity

Our global commons – the land, seas and atmosphere we share, and the ecosystems they host – are under severe threat from human activities.

We can have cities that are attractive and
 productive, where we can move and breathe,
and where communities flourish.

We are at risk of irreversibly damaging the natural assets of the planet that allow human communities to thrive and prosper.

Our world is being depleted of plant and animal species at an alarming rate, our natural landscapes and productive agricultural land are becoming progressively degraded, and our cities are choking from air pollution and congestion. In addition to this, our atmosphere is filling up with greenhouse gases that are pushing us towards the potentially catastrophic impacts of climate change.

We are making the world a more hostile and difficult place for ourselves and for future generations. But we have the opportunity to save and preserve our global commons by implementing the global agenda created by the international agreements in 2015 on sustainable development, finance and climate change.

Read The Guardian story - “Only green growth can bring prosperity.”

Breaking the Cycle of Forest Loss in the Amazon

The Amazon is at risk of what has been described as a ‘die-back circle’, where forest loss increases as a result of reduced rainfall and human activities such as logging. Crucially, that reduction itself leads to yet more drought conditions. Human induced climate change also threatens to further reduce rainfall, exacerbating the situation. Being able to predict which regions of the Amazon are susceptible to this loss is therefore critical to avoid worsening conditions.

The Amazon is at risk of being
caught in a "die-back circle".

Towards this end, researchers have recently reported that the presence of a variety of tree species are a good indicator of the likelihood of survival for forest regions. Reporting in the journal ‘Nature Communications’, the lead-author Dr. Delphine Clara Zemp of the Potsdam Institute for Climate Impact Research, Germany, reminds us why this research matters by simply stating that, ‘The Amazon rainforest is one of the tipping elements in the Earth system.’

A self-sustaining but vulnerable system.

Read the Science and Technology Research News story - “Breaking the Cycle of Forest Loss in the Amazon.”

Humans create carbon emissions which spawn Australia's extreme weather – report

Carbon emissions from human activities have driven significant changes to the climate in Australia, including about 1C of warming and an increase in extreme hot days and fire weather, according to the latest State of the Climate report released by the CSIRO and Bureau of Meteorology.

This year the report includes new information on the cause of extreme weather, pointing the finger clearly at carbon emissions from human activities, as well as the latest findings on warming in the oceans.

The report said record hot average daytime temperatures in 2014 were mostly caused by the extra carbon dioxide in the atmosphere. Researchers found that without the greenhouse gases, the daytime temperatures would have been warm but not record-breaking.

Similarly, another study discussed in the report found that record-breaking temperatures in September 2013 were 85% a result of carbon emissions, and 15% due to natural variations in temperature.

Read Michael Slezak’s story in The Guardian - “Humans create carbon emissions which spawn Australia's extreme weather – report.”

What people get wrong about climate change - VOX

It's widely recognized now that the global climate is increasingly a product of human activities. But less understood is how human activities are a product of the global climate.

The chart below shows what life was like for much of human history. Using data from ice cores, it indicates how temperatures varied over time. Notice the relatively flat line over the past 10,000 years — that's when agriculture began:

Read the VOX story - “What people get wrong about climate change.”

CSIRO survey reflects badly on Australian society's grasp of scientific knowledge

T

he CSIRO has just published what is one of the most depressing charts I have ever seen. It is depressing partly because of the consequences it implies, and partly because it reflects incredibly badly on Australian society’s understanding and appreciation of scientific knowledge.

The depressing chart below illustrates the headline finding of a CSIRO survey of Australian attitudes to climate change. It indicates that more than half of Australians don’t think that human activities, which are increasing the concentration of greenhouse gases in the atmosphere, are driving climate change.

Read the Climate Spectator story - “It’s just common sense - the depressing charts behind global warming stupidity.”

We 'chatter' as our options continue to vanish

Options of avoiding catastrophic climate change are quickly becoming fewer.

Accurate measurements show the
 continual rise of Co2 levels.

We knew with near certainty in the late 1980s that human activities were loading the atmosphere up with carbon dioxide and so changing its chemical make-up, and yet we have done effectively nought.

Had we responded to the warning given to the U.S. Congress then by NASA’s James Hansen with the intent his advice warranted we would have been facing a decidedly different future.

Ideological and psychological differences fuelled, what those of Hansen’s ilk considered idle and time wasting chatter contributing nothing to resolving the dilemma facing humanity.

When Hansen talked with Congress the carbon dioxide content in the atmosphere was just over 340 parts per million (ppm) and then it was considered that the upper safe limit was 350ppm.

James Hansen.

We have now passed 400ppm; global temperatures have increase by about one degree Celsius and still the global chatter is drowning out the reality of what needs to be done.

Preindustrial age carbon dioxide concentrations were about 280ppm and at the turn of the century, they were closing in on 370ppm.

The present Abbott-led Coalition Government has set an unconditional target of reducing Australia’s greenhouse gas emissions (GHG) to five per cent below 2000 levels by 2020 and 15 to 25 per cent, conditional on the extent of international action.

The Australian Government has also committed to a long-term target to cut pollution by 80 per cent below 2000 level by 2050.

The five per cent below 2000 levels by 2020 is absolutely inadequate and the likelihood to the 2050 goal being realised would be laughable if the lives of many were not at stake.

James Hansen has argued that a safe climate future for humans and all other life forms on earth rest with the achievement and maintenance of a GHG level of 350ppm. That’s gone and the likelihood of you or me ever seeing that again is not only gone, but barely a memory.

The business as usual world careers on largely unchecked and every indication at this point is that the world will see a four degrees Celsius, at least, increase by the end of this century.

Descriptions of what our world will be like by then are depressing and decidedly different.

It is however, not so much a matter of what do we do for what we have done to earth’s atmosphere will leave the instruction book in the hands of another – nature.

Climatologists of the world generally agree that for us to have any chance at all, we need to stop our GHG emissions right now, not by five per cent below 2000 levels in 2020, but by 100 per cent today.

Impossible, of course, but one step that would make a significant difference and begin our preparation to live in a world unlike anything ever seen in human history , begins with ending our seemingly insatiable list of wants and determining how we replace them with ways we can answer our needs.

The idea of a Four-Hour Work Day, not including public services or farmers, and not permitting overtime or double shifts, would substantially change societal dynamics, building stronger neighbourhoods, communities, towns and cities and within that create the resilience we will urgently need as our energy reserves become even more depleted and the climate changes to become hugely unpredictable, unreliable and foreign to the seasons most people now understand and depend upon to ensure their survival.

Our survival, literally, depends upon us understanding how economics have infiltrated every level of living and how we need to urgently dethrone it to replace it with broader, deeper and greater understanding that success is not about accumulation, rather in bonding with your fellows and sharing.

The Four-Hour Work Day is not about success as it is traditionally understood; it is about building resilience and adaptability.

Robert McLean.

 

Climate change is continuing

Multiple lines of evidence show that global warming continues and that human activities are mainly responsible.

The fundamental physical and chemical processes leading to climate change are well understood. CSIRO and Bureau of Meteorology observations provide further evidence that climate change is real. The scientific understanding and the observations show that global trends in temperatures and sea level rise since the mid-20th century have been caused predominantly by human activities.

Natural climate variability also affected global-mean temperature and sea level during the past century, but much less than increasing greenhouse gases.

Read the whole report -