Tag Archives: greenhouse gas

Melting Antarctica could double sea level rise

Unabated greenhouse gas emissions could lead to sea level rise twice as high as we had anticipated, according to a recent study published in Nature.

By the end of this century, scientists predict that sea levels could rise by over 2 meters on average. Note that this is a global average, meaning that some areas could see much higher local rises in sea level. For Small Island Developing States, this could mean the end of their existence altogether. The research has been welcomed by the scientific community, who had already raised reservations with regards to what was called “very conservative” estimates of sea level rise caused by a changing climate.

So what has changed, how could we suddenly double sea level rise? The answer lies in complex processes involved in the melting of ice in Antarctica. Previous estimates had failed to take into account accelerated melting caused by disintegrating ice sheets. In fact, scientists had only been able to consider the melting ice shelves due to increased air and water temperatures, and had ignored the impact of surface melt-water and rainfall which can help fracture large chunks of ice.

Thwaites_glacier_NASA
The Thwaites glacier is one of the fastest flowing glaciers off Antarctica. Source: Jim Yungel/NASA

Climate change adaptation has been hailed as the ultimate recourse to prevent negative impacts of sea level rise. For instance, in a number of coastal regions, ecosystem-based adaptation helped by mangroves has been underway for some years already. Mangroves play a significant role in protecting coastal regions from intense storms including typhoons, expected to increase in frequency with climate change. Combined with sea level rise, such storm could be catastrophic, especially in densely populated areas.

Mangrove_Peyri_Herrera_Flickr2
Mangrove forests like these help protect coastal communities against storms and storm surges.

In previous adaptation planning, the unique property of mangroves to “grow soil” had been counted on to mitigate the impacts of rising sea levels. The rate of growth of mangroves was very much in line with previous climate change projections, yet this new data would suggest that these fragile ecosystems would no longer be able to keep up with the increased rate of sea level rise. Hence, millions of the most vulnerable coastal communities will likely have to rethink their adaptation strategies, a very costly endeavour.

So what is the silver lining? If we achieve the targets set in the 2015 Paris Agreement, sea levels will continue to rise, but never to the rate which would occur if Antarctica’s melting was to start accelerating. Coastal communities will still need to adapt, but costs will be reduced and lives will be saved.

Our impact on the Earth

Here’s an impressive and rather scary visual of our impact on the earth, via the World Economic Forum.

“We must. We can. We did!” Historic Paris Climate Agreement adopted

A historic agreement to tackle climate change and pave the way towards a low carbon, greener and cleaner future has been adopted by 195 nations in Paris.

This was a truly monumental political achievement that was only possible because of the deep urge felt unanimously by all member nations to act on one of the greatest challenges humanity has ever faced; that the climate is changing with disastrous consequences for people all over the world.

The Paris Agreement’s main aim is to limit global warming to well below 2 degrees Celsius by the end of the century and to drive efforts to limit temperature increase to 1.5 degrees.

The 1.5 degree Celsius limit is a significantly safer defence line against the worst impacts of a changing climate.

To reach these ambitious goals will require collaboration in a global scale, with richer nations providing much of the financial and technological means to implement low carbon, green initiatives throughout the world.

French President Francois Hollande told the assembled delegates: “You’ve done it, reached an ambitious agreement, a binding agreement, a universal agreement. Never will I be able to express more gratitude to a conference. You can be proud to stand before your children and grandchildren.”

Over the next few weeks I will be posting about the key implications of this agreement.

 

Details of the Paris Agreement can be found:
[1] http://unfccc.int/meetings/paris_nov_2015/in-session/items/9320.php
[2] http://newsroom.unfccc.int/unfccc-newsroom/finale-cop21

A love poem for the Earth #showthelove

Yesterday was National Poetry Day, so here are some celebrities reading a simple love sonnet. We can protect the planet we love!

“So long as men can breathe, or eyes can see,
So long lives this, and this gives life to thee.”
– Sonnet 18, William Shakespeare

Islamic scholars call for action on climate change

A declaration by Islamic scholars calls on global leaders to reduce greenhouse gas emissions and suggests that Muslims have a religious duty to tackle climate change.

The Islamic Declaration on Global Climate Change, drawn up by a group of academics, Muslim scholars and international environment policy experts, was announced recently at a symposium on Islam and climate change in Istanbul. It calls on the 1.6 billion Muslims around the world to phase out our reliance on fossil fuels and switch instead to clean energy from renewable sources.

The statements reiterates the now well documented rise in global average surface temperatures since the industrial revolution and attributes this increase to excessive burning of fossil fuels.

It states that:
“This current rate of climate change cannot be sustained, and the Earth’s fine equilibrium (mīzān) may soon be lost.”

The declaration laments the slow progress of international climate-change negotiations:
“It is alarming that in spite of all the warnings and predictions, the successor to the Kyoto Protocol which should have been in place by 2012, has been delayed.”

It calls on global leaders, who will be meeting in Paris this December, to come to an “equitable and binding conclusion” and commit to a 100 % renewable energy and/or a zero emissions strategy.

The Islamic declaration follows a similar call to action by Pope Francis in his encyclical Laudato Si’ in June this year.

“All the faiths are talking about climate change,” says David Shreeve (via Nature), environmental advisor to the Church of England’s Archbishop’s Council. “It’s great that the Muslims are putting out a declaration, because whatever your faith, it’s a great opportunity for the faiths to stand up and say we really are concerned about this.”

The declaration ends with a reminder to all Muslims of a verse in the Qur’an –

وَلاَ تَمْشِ فِي الأَرْضِ مَرَحًا إِنَّكَ لَن تَخْرِقَ الأَرْضَ وَلَن تَبْلُغَ الْجِبَالَ طُولاً

Do not strut arrogantly on the earth.
You will never split the earth apart
nor will you ever rival the mountains’ stature.
Qur’an 17: 37

Read the full declaration here: http://islamicclimatedeclaration.org/islamic-declaration-on-global-climate-change

China’s carbon emissions may have been overestimated

An analysis of two major sources of China’s carbon dioxide emissions suggests that the country’s carbon emissions may have been overestimated in recent years.

China’s carbon emissions from burning fossil fuels and cement production are significantly lower than previous estimates. About 14% less in 2013 compared to estimates by the Chinese government and others according to research published in Nature this week.

About three quarters of the growth in carbon emissions from the burning of fossil fuels and cement production between 2000 and 2012 occurred in China. These helped to sate China’s booming energy thirst and boost its economy from around US $3,500 GDP per Capita in 2000 to over $8,000 in 2012.

A Chinese coal power plant. Source: WC/Tobias Brox
A Chinese coal power plant. Source: WC/Tobias Brox

The actual amount of carbon dioxide emissions from two major sources: burning fossil fuel and cement production has been plagued with uncertainties. The new study led by Zhu Liu from Harvard University re-evaluates data from 4,200 Chinese mines and incorporates new measurements of the emission factor of coal.

The team found that China’s carbon emissions from these two sources have been consistently overestimated.

“At the beginning of the project we thought that the emissions might be higher” than existing estimates, says Zhu Liu. “We were very surprised.”

Despite these new revisions to carbon emissions China is still the world’s largest emitter of carbon dioxide. Even when the lower estimates are taken into account, China’s carbon emissions for 2013 was still more than two-thirds higher than the second largest emitter, the United States.

Nevertheless, the new estimates represent a substantial decrease in annual global carbon emissions in 2013 by 0.35 GtC (billion tons of Carbon), an amount larger than the reported increase in global emissions between 2012 and 2013.

More information:
[1] Read the full paper here: http://www.nature.com/nature/journal/v524/n7565/full/nature14677.html
[2] http://www.nature.com/news/china-s-carbon-emissions-overestimated-1.18199
[3] http://www.nature.com/news/2007/070618/full/news070618-9.html

“So long, and thanks for all the fish” … the end of coral reefs?

Leading scientist says that even ambitious greenhouse gas reduction targets will not be able to save the world’s coral reefs.

Professor Peter Sale from the University of Windsor, Canada claims that coral reefs, as they were 50 years ago, cannot be saved from climate change – even if the climate change talks in December this year (COP21) are “wildly successful”.

Professor Sale unveiled the depressing results today at the Goldschmidt conference, a gathering of the world’s top geochemists in Prague.

He said, “Even if Paris is wildly successful, and a treaty is struck, ocean warming and ocean acidification are going to continue beyond the end of this century. This is now serious; I find it very unlikely that coral reefs, as I knew them in the mid-1960s, will still be found anywhere on this planet by mid-century. Instead, we will have algal-dominated, rubble-strewn, slowly eroding limestone benches.”

A bleached coral. These events will become more common with global warming.
A bleached coral. These events will become more common with global warming.

Globally coral reefs are generally found in tropical waters. Not only are they some of the world’s most productive ecosystems they also deliver ecosystem services in tourism, fisheries and coastline protection. The global economic value of coral reefs has been estimated to be US $375 billion per year!

Loss of reefs will be a fatal blow for the animals and communities who rely on them

While the global policy debate has been about trying to limit global warming to 2 degrees by the end of the century, Professor Sale claims that this won’t be enough to save coral reefs.

“I see little hope for reefs unless we embark on a more aggressive emissions reduction plan. Aiming for CO2 at 350ppm, or a total warming of around 1°C is scientifically defendable, and would give reefs a good chance; a number of coral reef scientists have called for this.”

Sale summarised:

“Knowing what we are doing, do we have the ethical right to eliminate an entire ecosystem from this planet? It’s never been done before. But watching as our actions lead to the loss of all coral reefs on the planet is like removing all rainforests. I don’t believe we have that right”.

Obama reveals “biggest, most important step” towards tackling climate change

President_Barack_Obama“I believe there is such a thing as being too late.”
– President Obama

Yesterday President Obama unveiled his “biggest, most important step” towards tackling the affects of climate change,

The proposed Clean Power Plan has been billed as the strongest action ever on climate change by a US president.

According to the proposed plans, the U.S. will cut levels of greenhouse gas emissions to a third of 2005 levels in the next 15 years. The measures include significant advancements in solar, wind and other renewable energy sources.

Key points of Obama's Clean Power Plan
Key points of Obama’s Clean Power Plan

“No challenge poses a greater threat to our future, and future generations than a changing climate.”
– President Obama

White House adviser Brian Deese said the Environmental Protection Agency (EPA) rules represented the “biggest step that any single president has made to curb the carbon pollution that is fuelling climate change”

The full press conference can be viewed here:

More information:
[1] https://www.whitehouse.gov/climate-change
[2] http://www.bbc.co.uk/news/world-us-canada-33753067

The Silk Road helped form a hidden carbon sink under the desert

Scientists have found a potentially large carbon sink in the most unlikely place on Earth – under the desert. The increase in carbon storage is linked with the rise of farming in arid landscapes.

This surprising conclusion comes from work done in the Tarim Basin of western China by Chinese and American scientists. The results are published in the journal Geophysical Research Letters.

“Basically, people thought the whole arid region is totally negligible to the global carbon budget,” says lead author Yan Li of the Chinese Academy of Sciences in Urumqi. “We are arguing that that’s not the case.”

Li and colleagues measured and dated the carbon content of water samples taken from a salty aquifer beneath the Tarim Basin. They show that the rate at which carbon sunk into the aquifer rose dramatically with the rise of farming and agriculture in the region. Rate of carbon storage increased by more than 12 times previous levels over the past 8000 years with particularly high levels beginning around 2000 years ago when the Silk Road opened.

How it works

The process began when humans started to grow crops on sandy soil. As the plants take in carbon dioxide from the air, some is released into the sand. Farming in desert conditions requires a lot of water to combat rising salinity caused by rapidly evaporating water. This organic carbon dissolves in the water and is transported down through the sand into deed salty aquifers.

Li_etal_2015
A schematic diagram showing the leaching and transport of DIC (dissolved inorganic carbon) in a closed arid basin. Source: Li et al, 2015

Normally these aquifers are tapped by rivers and streams and so the carbon comes back out of storage. But in the Tarim Basin the aquifer is a closed system, meaning that water does not escape, effectively locking away the carbon.

Li expects this process to occur in deserts around the globe but the amount of carbon would vary depending on the pH of the soil and the level of farming activity.

The results from this study will have important implications for the study of the global carbon cycle as desert regions were previously thought to be unimportant for carbon storage.

Read the full study here: http://onlinelibrary.wiley.com/doi/10.1002/2015GL064222/abstract

Climate change explained in 60 seconds

Climate science explained in 60 seconds by the Royal Society and the US National Academy of Sciences.