A remote South Pacific island has the highest density of plastic debris reported anywhere on the planet, our new study has found.
Our study, published in the journal Proceedings of the National Academy of Sciences, estimated that more than 17 tonnes of plastic debris has washed up on Henderson Island, with more than 3,570 new pieces of litter arriving every day on one beach alone.
The Paris deal calls for governments to pursue the aim of keeping global warming below 1.5℃. But our results suggest that we could hit that level before the end of the next decade if the Pacific Ocean moves into a state we have nicknamed the “cranky uncle” for its effects on global temperatures.
Global temperature records have tumbled in recent years: 2016 was the world’s hottest year on record, the third record-breaking year in a row.
Although human emissions of greenhouse gases are the primary driver of these rising temperatures, there are other factors at play. The climate system is an unwieldy beast, containing a variety of erratic feedbacks and complex mechanisms.
One mechanism with which many people are familiar is El Niño and La Niña, a see-sawing of warm waters across the tropical Pacific every two to seven years. Climate scientists were not at all surprised to see record global temperatures in 2015 and 2016, because of the large El Niño that ended last year.
Another, lesser-known cycle in the Pacific Ocean is the Interdecadal Pacific Oscillation (IPO). Since El Niño and La Niña are Spanish for the “the boy” and “the girl”, we have nicknamed their slower-moving relatives the “cranky uncle”, El Tío, and the “kind auntie”, La Tía.
Like El Niño, warm phases of the IPO provoke a temporary acceleration in global temperature, but over much longer periods, lasting between 10 and 30 years.
The cool La Tía phase of the IPO since around 2000, and its associated slowdown in the rate of global warming, may have lulled us into a false sense of security.
Scientists are now concerned that the next El Tío phase could be on its way, which might sustain the relatively rapid global warming seen over the past few years.
With this in mind, we decided to investigate how soon we are likely to surpass the 1.5℃ level, both with and without the influence of the IPO.
We used climate model simulations to project global temperatures. The models show temperatures varying significantly from year-to-year and decade-to-decade, as we see in the real world. The centre point of the model projections indicates that the 1.5℃ level would be reached just before 2030, with 75% of the model projections crossing 1.5℃ before 2032.
With the recent slowdown period in mind, we wondered how the next IPO phase, El Tío or La Tía, would influence global temperature. We found that the rate at which global average temperature approaches the 1.5℃ level is influenced significantly by the IPO.
El Tío phases are responsible for an acceleration in global temperature. The centre point of the El Tío projections passes the 1.5℃ level in around 2027, and a quarter of our projections pass 1.5℃ as early as 2024.
For La Tía, the projected rate of warming is reduced, and the centre year is 2031 – the kind auntie gives us a little more breathing space.
So, is the Paris agreement a failure?
No. The Paris agreement is a critically important step in the right direction.
Although we will soon surpass the 1.5℃ warming benchmark, we still have a chance to turn around and head back down the hill. But to reduce global temperatures, we need not only to reduce our net emissions to zero, but to move swiftly into net negative carbon emissions territory. That means that overall we will need to take carbon dioxide out of the atmosphere, not add more.
But we are a very long way from that point. There is a lot of work to do.
For the next few decades we have to accept that we are likely to see more extreme events as the effect of continued rising global temperatures takes its toll.
We can’t hide from our cranky uncle, but we can limit climate change and its impacts. Although the political will for evidence-based climate policy seems to be waning in some quarters, the message from climate scientists has not changed:
We need swift global cooperation to dramatically reduce atmospheric greenhouse gas concentrations.
These islands lost to the sea range in size from one to five hectares. They supported dense tropical vegetation that was at least 300 years old. Nuatambu Island, home to 25 families, has lost more than half of its habitable area, with 11 houses washed into the sea since 2011.
This is the first scientific evidence, published in Environmental Research Letters, that confirms the numerous anecdotal accounts from across the Pacific of the dramatic impacts of climate change on coastlines and people.
However, these studies have been conducted in areas of the Pacific with rates of sea level rise of 3-5 mm per year – broadly in line with the global average of 3 mm per year.
For the past 20 years, the Solomon Islands have been a hotspot for sea-level rise. Here the sea has risen at almost three times the global average, around 7-10 mm per year since 1993. This higher local rate is partly the result of natural climate variability.
These higher rates are in line with what we can expect across much of the Pacific in the second half of this century as a result of human-induced sea-level rise. Many areas will experience long-term rates of sea-level rise similar to that already experienced in Solomon Islands in all but the very lowest-emission scenarios.
Natural variations and geological movements will be superimposed on these higher rates of global average sea level rise, resulting in periods when local rates of rise will be substantially larger than that recently observed in Solomon Islands. We can therefore see the current conditions in Solomon Islands as an insight into the future impacts of accelerated sea-level rise.
We studied the coastlines of 33 reef islands using aerial and satellite imagery from 1947-2015. This information was integrated with local traditional knowledge, radiocarbon dating of trees, sea-level records, and wave models.
Waves add to damage
Wave energy appears to play an important role in the dramatic coastal erosion observed in Solomon Islands. Islands exposed to higher wave energy in addition to sea-level rise experienced greatly accelerated loss compared with more sheltered islands.
Twelve islands we studied in a low wave energy area of Solomon Islands experienced little noticeable change in shorelines despite being exposed to similar sea-level rise. However, of the 21 islands exposed to higher wave energy, five completely disappeared and a further six islands eroded substantially.
The human story
These rapid changes to shorelines observed in Solomon Islands have led to the relocation of several coastal communities that have inhabited these areas for generations. These are not planned relocations led by governments or supported by international climate funds, but are ad hoc relocations using their own limited resources.
The customary land tenure (native title) system in Solomon Islands has provided a safety net for these displaced communities. In fact, in some cases entire communities have left coastal villages that were established in the early 1900s by missionaries, and retraced their ancestral movements to resettle old inland village sites used by their forefathers.
In other cases, relocations have been more ad hoc, with indivdual families resettling small inland hamlets over which they have customary ownership.
In these cases, communities of 100-200 people have fragmented into handfuls of tiny family hamlets. Sirilo Sutaroti, the 94-year-old chief of the Paurata tribe, recently abandoned his village. “The sea has started to come inland, it forced us to move up to the hilltop and rebuild our village there away from the sea,” he told us.
In addition to these village relocations, Taro, the capital of Choiseul Province, is set to become the first provincial capital in the world to relocate residents and services in response to the impact of sea-level rise.
The global effort
Interactions between sea-level rise, waves, and the large range of responses observed in Solomon Islands – from total island loss to relative stability – shows the importance of integrating local assessments with traditional knowledge when planning for sea-level rise and climate change.
Linking this rich knowledge and inherent resilience in the people with technical assessments and climate funding is critical to guiding adaptation efforts.
Melchior Mataki who chairs the Solomon Islands’ National Disaster Council, said: “This ultimately calls for support from development partners and international financial mechanisms such as the Green Climate Fund. This support should include nationally driven scientific studies to inform adaptation planning to address the impacts of climate change in Solomon Islands.”
Last month, the Solomon Islands government joined 11 other small Pacific Island nations in signing the Paris climate agreement in New York. There is a sense of optimism among these nations that this signifies a turning point in global efforts.
However, it remains to be seen how the hundreds of billions of dollars promised through global funding models such as the Green Climate Fund can support those most at need in remote communities, like those in Solomon Islands.
Simon, Alistair and Javier will be on hand for an Author Q&A 2-3pm Monday May 9 2016. Leave your comments below.
While all of us of will experience the effects of climate change most are not facing the inevitable disappearance of our country. Yet that is the case for the 92,000 inhabitants of Kiribati, as well as other low-lying island states across the planet.
With its nation dispersed over more than 20 islands, some increasingly subject to ocean flooding, the Kiribati government has purchased land in Fiji to relocate some of its inhabitants. Over the coming century Kiribati, along with every other maritime region, faces rising seas driven by oceans expanding as they warm, and by melting ice sheets and glaciers.
Ahead of the Paris climate conference, which begins on November 30, Kiribati’s president Anote Tong has issued a call for a moratorium on new coal mines. On his recent visit to Melbourne I spoke to President Tong about the prospects for Kiribati in a warming world, and efforts to mitigate the worst impacts.
End coal to saving drowning islands
President Tong related that his call for a coalmine moratorium has had a sympathetic hearing from US President Barack Obama. He and former Australian Prime Minister Tony Abbott talked amiably but (at best) agreed to disagree. As yet, he has been unable to meet with Abbott’s successor Malcolm Turnbull.
What impressed me particularly is that, just as indigenous Australians relate to the land, President Tong was deeply passionate that the islands of Kiribati are the ancient, ancestral home of his people.
President Tong however is under no illusion that anything will happen quickly when it comes to weaning the world off coal. He points out that coal-fired power stations will be needed in the medium-to-long term to heat the colder northern countries.
Finding a coal alternative
There are several hurdles to cross in the transition away from fossil fuels. While 100% renewable energy may be possible, nuclear fission reactors may be needed as part any low carbon, coal free future for Europe, at least in the medium term. Nuclear generation has long dominated the power sector in France. Germany has made enormous efforts with renewables but they are (following the Fukushima disaster) using more coal as a consequence of phasing out nuclear, a move many climate scientists consider to be irresponsible.
China and South Korea are aggressively expanding their capacity for nuclear power generation, though China is also continuing to build coal plants.
Still, some nation states are determined to kick the coal habit as soon as possible. The UK has committed to closing its remaining coal fired plants by 2025 and will, instead look to nuclear, natural gas and renewables. The UK has long used some nuclear power, and there have also been innovative moves towards renewables and the use of domestic waste for the local co-generation of heat and electricity. And, as is the case for us in Australia, their coal-fired plants are old and in need of replacement.
When it comes to renewables, Australia has the advantage of being a massive solar and wind collector, with 23 million electricity–hungry humans versus 63 million in the UK. We have plenty of coal seam gas, although the concern here is that the leakage of methane (CH₄) from poorly-maintained wellheads negates its 50% (in CO₂ emissions) advantage over coal. However piped gas is much more efficient for local, small scale “trigeneration”.
Are we willing (or do we need) to open out the nuclear discussion here? It would be great to see a national debate on energy generation with everything on the table. Hopefully, the national dialogue may improve somewhat when the dust settles following the next federal election.
Coal might to some extent be saved by carbon capture and storage (CCS) but, even if the local geology is right, this is only likely to happen if an appropriate price is placed on carbon emissions. A direct carbon tax may work better than cap and trade schemes though, for political reasons, the latter (or some variation) may now be the only possibility in Australia. And, if there is a realistic versus a token carbon price, how does the economics of CCS rate against renewables and storage?
Talking with President Tong, he had no illusions concerning either the morality of national governments or their independence when it comes to legislating against the perceived self-interest of extraordinarily wealthy, and often globalised, vested interests, particularly fossil fuel companies.
But, as Australian citizens have the enormous privilege of being able to debate and to vote in an open and democratic nation state, shouldn’t we be addressing the issue of possible consequences of our energy consumption and fossil-fuel export economy?
Apart from the possibility of taking the wrong direction and focusing on what will inevitably be stranded assets, what will the liability situation be for the mining companies, the coal exporting nations and their leaders and citizens if the consequences of global warming are as dire as predicted?
BHP Billiton is facing ongoing costs over the collapse of its local joint-owned tailings dam in Brazil. Global warming threatens unprecedented damage on a global scale, including the loss of small, vulnerable countries such as Kiribati. How should we account for the responsibility of rich nations such as Australia? Perhaps we will see accountability similar to the reparations exacted from Germany after the First World War, or even more severe costs.
The concept “think globally, act locally” has been attributed (in 1972) to New York microbiologist René Dubos. That accurately describes the reality of actions that might limit the impact of global warming. One thing we can do locally is vote.
Australia is a basically decent country. Few Australians would surely wish to see themselves as acting against the best interests of future generations. But we are known by our actions. We need a broad and informed debate on what we can do to limit global warming and, in the process, ensure our own longterm well-being. Can we seize the future with all its possibilities, or must we be locked into an ultimately unsustainable pattern of repeating the past?