How to Think About 1.5 Degrees

Clive Hamilton, Charles Sturt University

Astonishment was universal last December when the Paris Agreement on climate change included the aspiration to limit warming to 1.5 degrees above pre-industrial levels, a much tougher target than the standard of 2 degrees, now seen as too risky.

It was a remarkable triumph for a long campaign by the small island states, proving that even tiny nations, armed with a powerful moral case, can change the world.

But what does a global aim of 1.5 degrees mean? Is it achievable? How much difference would it make? A conference at the University of Oxford two weeks ago brought together leading scientists to begin to answer these questions.

No one can give firm answers, but some surprising observations emerged at the conference. One thing is clear: given the vast quantity of carbon dioxide already in the atmosphere, with more still to come, limiting warming to 1.5 degrees will require ‘negative emissions’.

Negative emissions technologies aim to draw carbon dioxide out of the atmosphere and store it safely. Some proposed technologies include machines that extract carbon dioxide from the air, concentrate it and then somehow (the answers are vague) store it. At a scale to make a significant difference, a huge infrastructure of carbon-sucking machines, concentrating equipment and pipelines would need to be built.

The most commonly mentioned method of negative emissions entails generating electricity by burning biomass – mainly crop waste, wood waste, and crops grown for the purpose – capturing the carbon dioxide from the emissions and storing them underground.

It’s estimated that to make a substantial difference to global warming huge expanses of land would have to be given over to growing biomass crops. This risks depriving poor people of food crops and destroying ecosystems as swathes of land are converted to growing biomass for energy.

So here is the first troubling prospect. Although warming of only 1.5 degrees would result in much less harm to the climate than 2 degrees, it’s possible that the ecological damage caused by the negative emissions projects needed to get there may exceed the benefits, at least for some. The ecosystem costs of the emission reduction pathways may outweigh the benefits of lower warming.

So while the overall goal of climate negotiations is to avoid ‘dangerous climate change’, perhaps it needs to be changed so that the goal becomes to ‘minimize dangerous change to the Earth System as a whole’, a dramatic shift in how we think about the issue.

It must begin soon

For a 1.5-degree goal, large-scale negative emissions activity would need to begin soon, before 2030, and expand rapidly, so that by 2050 or sooner the amount of carbon sucked out of the atmosphere would have to exceed the amount emitted into it from fossil fuel burning.

No one is confident it can be done. Some suggest that when the Intergovernmental Panel on Climate Change has included negative emissions in its future emissions scenarios it is not much more than a ‘fudge factor’ to make the 2 degrees limit seem possible.

Apart from the cost, the biggest obstacle to negative emissions technologies is what to do with the captured carbon. Although it’s fairly easy to extract carbon dioxide from the air, no one has yet come up with a feasible and economic way of storing billions of tonnes of it. It must be done safely and it must stay there for thousands of years, without leaking out.

Some years ago governments became excited at the idea of pumping it into geological formations, but pilot projects around the world have been abandoned because they ran into technical problems and cost blowouts. Now it’s thought that storing carbon dioxide underground on a large scale is decades away.


The world has already warmed by 1 degree and momentum in the climate system will almost certainly see the world reach 1.5 degrees, perhaps as early as 2030. So if our goal is to limit warming to 1.5 degrees there will be an ‘overshoot’, taking warming to at least 2 and perhaps 3 degrees, before the average global temperature can be brought back down.

Here is the second troubling possibility. If the world warms by 2 or more degrees will feedback effects kick in – such as unstoppable melting of the Siberian permafrost, which could send more greenhouse gases into the atmosphere, making it virtually impossible to stabilize warming at 2 degrees, let alone 1.5.

And if we could overshoot and return to 1.5 degrees, would ecosystems and vulnerable plant and animal species be able to survive the period of perhaps three or four or five decades of overshoot. Scientists hope that ecosystems possess ‘temporary resilience’ during the overshoot period so that they can bounce back when cooler conditions return.

Equally troubling, for those creatures and ecosystems that do manage to adapt to an environment 2 or 3 degrees warmer, could they cope in a cooling environment as the global temperature is wound back to 1.5 degrees?

When the nations of the world in Paris adopted the 1.5 degree aspiration the politicians were well ahead of the scientists. Now the scientists are scrambling to catch up.

This article was first published by Scientific American.

The Conversation

Clive Hamilton, Professor of Public Ethics, Centre For Applied Philosophy & Public Ethics (CAPPE), Charles Sturt University

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


The story behind Australia’s marine reserves, and how we should change them

Colin Buxton, University of Tasmania and Peter Cochrane, Australian National University

The federal government is considering changes to Australia’s marine reserves to implement a national system. This week The Conversation is looking at the science behind marine reserves and how to protect our oceans.

Australia has the third largest marine jurisdiction in the world, a vast ocean territory that contains important natural and biological resources. The oceans separate us from, and connect us to, the rest of the world.

They supply food, play a significant role in determining our climate, and are fundamental to our national identity. Protecting our oceans is of paramount importance and Australia is signatory to several international agreements and conventions to establish a network of marine reserves aimed at looking after marine resources.

In 2012 the Australian government declared a network of marine reserves to conserve our marine environment. In 2014, we were asked to co-chair a review of the reserves, with the results released this September.

We looked at five marine regions (North, North-West, South-West, Temperate East and the Coral Sea) but not the South-East network which had been established in 2007. Of the 40 reserves administered by the commonwealth government, we recommended changes to 26.

Click on the marine reserve regions in the map below to details of the changes proposed.

The review was established to address stakeholder concerns about how the reserves were zoned – and what activities were allowed in each zone – as well as ensuring that zoning decisions were informed by the best available science.

One of the strong messages we received was that people were tired of the process – having been asked about the same concerns when the reserves were declared. But the opportunity to raise concerns and suggest solutions was quickly taken up.

We held more than 260 meetings with more than 650 people between February and August 2015, considered 13,124 written submissions, the vast majority from individuals, and received 1,859 responses to an online survey.

What has changed?

The primary goal of the National Representative System of Marine Protected Areas (NRSMPA) is to create a system of reserves that is comprehensive (includes the full range of ecosystems within and across each bioregion), adequate (ensures ecological viability and the integrity of populations, species and communities) and representative (reasonably reflects the biodiversity of the marine ecosystem). This will ensure our marine ecosystems stay healthy for generations to come.

Zoning allows us to regulate activities within marine reserves without detracting from their conservation value. These zones range from no-take, which doesn’t allow any resource extraction (such as fishing or mining), through to multiple use and special purpose zones, where certain uses are, or may be, allowed, subject to an assessment of their potential impacts.

We made seven major recommendations:

• Put more conservation features such as seafloor types, canyons, reef, slope and shelf in no-take protection (from 331 to 352 of the 509 primary conservation features recognised in the reserves).

• Increase the area of no-take zones in four regions, but reduce the area of no-take zone to 41% of the Coral Sea. This means the overall proportion of no-take across the 40 reserves drops marginally from 36% to 33% – the same level as the Great Barrier Reef Marine Park.

• An 81% increase in the area zoned as Habitat Protection Zone (HPZ) – an additional 450,000 square kilometres – rising from 24% to 43% of the estate; and add more conservation features in the HPZ – (from 192 to 272 of the 509 conservation features).

• A 27% increase to just over three quarters (76%) of the overall area of the estate receiving a high level of protection under Sanctuary Zone, Marine National Park Zone or Habitat Protection Zone; all these zones prohibit activities such as seabed mining and fishing that damages the seafloor.

• The total area zoned as Multiple Use Zone is halved, from 36% to 18% of the estate.

• Protection for the coral reefs in the Coral Sea is improved (three additional reefs – Holmes, South Flinders and Wreck – zoned as national park, and all 34 reefs zoned as sanctuary, national park, or habitat protection, and notably improving protection of the reefs of the Marion Plateau).

• Our proposed zoning in the Coral Sea to decrease national park zones and increase habitat protection more strongly reflects zoning in the adjacent Great Barrier Reef, effectively increasing the area of GBR green zones.

Clearly these changes do not support claims that the recommendations will “trigger a devastating loss of threatened marine life”. Nor do they represent “huge cutbacks to marine hotspots”, or “expanded mining”.

On the contrary, they represent a significant improvement to biodiversity included in no-take and other highly protected zones, and better conservation of key features such as southern coral reefs of the Coral Sea.

Who will this affect?

Commonwealth waters, starting at 3 nautical miles (about 5.5 km) from the coast, are generally beyond the safe reach of most recreational fishers and the direct influence of coastal communities.

Nonetheless, there were some areas of particular significance to the recreational fishing, charter fishing and dive tourism sectors such as the Perth Canyon and the Coral Sea, which were adversely affected by the reserves’ proclamation in 2012. The review recommendations accommodated almost all of these concerns through local solutions developed in close consultation with users and their representatives.

The guiding principles of the marine reserves include that zones are based on specific activities, and socioeconomic costs should be minimised.

We were particularly mindful of the socioeconomic importance of fisheries, especially to regional communities. Australia has been globally acknowledged for its management of fisheries. For instance, we recognised Marine Stewardship Certification (MSC) of tuna longlining in the Coral Sea and the Northern Prawn Fishery in our consideration of these two valuable fisheries.

We assessed the risk that certain fishing methods such prawn trawling, longlining and midwater trawling posed to marine habitats using the most up-to-date scientific information and understanding. Along with historical catch records, we used these to develop recommendations on zoning in the marine reserves.

For commercial fisheries that operate in Commonwealth waters, we consulted with users and industry peak bodies and found solutions that reduced impacts on these fisheries while improving the protection of conservation features. The outcome is that displacement of commercial fishing, and therefore adjustment cost to taxpayers (if any) is lower.

Due to the importance of energy security, the original reserve network design was constrained by largely avoiding areas of oil and gas prospects and leases. Where marine reserves and prospects co-exist the zoning is generally multiple use.

The review recommended several departures from this constraint. Much of the Bremer reserve in WA, an area where large fish, mammals and seabirds are known to aggregate, is proposed as a no-take national park, despite high petroleum prospects. Similarly, we recommended that mining and exploration activities be excluded from Geographe Bay.

In the North we proposed more protection in several reserves by extending areas under habitat protection and national park where prospects are low. We also recommended a significant extension of national park at the head of the Great Australian Bight, a well-known site where whales gather.

By-and-large the ports and shipping sectors are not affected by marine reserves. Safe passage of ships is guaranteed under the law of the sea. However, we proposed changes to the Dampier marine reserve to include a Special Purpose Zone for an area where there is existing high intensity port and shipping activity.

Finally, Indigenous groups and representatives also participated in the review. We recommended that Indigenous communities should be encouraged to explore future socioeconomic opportunities from activities in reserves in or near traditional sea country. These activities could include Indigenous rangers monitoring and managing marine reserves.

Where to from here?

We believe the review struck a considered, science-based and robust balance of marine user interests, while improving the protection of key conservation features. Its recommendations address almost all of the major areas of contention raised during the review.

There is no loss of area under conservation management (reserve outer boundaries are unchanged), more of the estate is more highly protected, yet the displacement of commercial fisheries has been reduced through careful zone adjustments.

The review provides a strong foundation for future generations to benefit from the conservation, appreciation and sustainable use of the marine reserves – as long as it is effectively managed and adequately resourced.

The Conversation

Colin Buxton, Adjunct Professor, Fisheries Aquaculture and Coasts Centre IMAS, University of Tasmania and Peter Cochrane, Adjunct Fellow Fenner School of Environment and Society, Australian National University

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