For more than four decades, the Chilean glaciologist Gino Casassa has studied the ice of Antarctica.
At the start of his career, he was sceptical about whether humans were causing climate change. Today, Casassa directs Chile’s leading Antarctic research organisation, the Chilean Antarctic Institute (INACH). And he sees a continent where human-wrought change is obvious.
In West Antarctica and the Antarctic peninsula, Casassa has watched as sea levels, tourist numbers and geopolitical tensions have all risen. The continent is now one of the geographies where the future of climate change is writ largest.
In conversation with Dialogue Earth, Casassa reflects on how scientific understanding of Antarctica has evolved, the challenges facing the Antarctic treaty system, and the decisions that will shape the continent’s future over the coming decades.
Dialogue Earth: When you began working in Antarctica in the early 1980s, did you imagine you would witness such profound change?
Gino Casassa: No. When I carried out my first research in Antarctica, in 1982, there was still some debate as to whether the planet might be entering a cooling period. I was sceptical for many years about human influence on climate change, because I thought there was still a lack of evidence.
But by the late 1990s, that evidence was already overwhelming. As a scientist, one must follow the scientific method and be prepared to change one’s mind when new data emerges. I went from being sceptical to being completely convinced that global warming is primarily man-made.
What convinced you that Antarctica was changing?
One of the most significant moments was when we took part in research in the Amundsen Sea, in West Antarctica, alongside scientists from NASA and the Chilean navy. There were indications that this region might be the continent’s Achille’s heel, and the data confirmed that it was indeed losing ice. At the same time, we were observing very rapid changes on the Antarctic peninsula, one of the regions warming the fastest.
Once a certain temperature is reached, the ice begins to melt regardless of any political debate
Until then, many people thought that Antarctica was a huge freezer, where changes occurred over timescales of thousands of years. What we saw was exactly the opposite: in some areas, changes could occur in just a few decades.
What discoveries changed the way scientists understand the stability of Antarctic ice?
One of the major debates centred on the role of floating ice shelves. Some scientists argued that, if they disappeared, the continental ice would remain virtually unchanged. Others, including myself, believed that these ice shelves acted as a natural brake on the ice behind them.
Observations showed that this brake was real. When a shelf collapses, the glaciers accelerate their flow towards the ocean. Cases such as the collapse of the Larsen B ice shelf, where thousands of years’ worth of ice disappeared in a matter of weeks, marked a paradigm shift. We also began to realise that some regions had already passed points of no return.
As the saying goes – one that I find very apt – the melting point of ice is non-negotiable. Once a certain temperature is reached, the ice begins to melt regardless of any political debate.
Antarctic policy has also changed. How do you view the developments there?
The Antarctic treaty remains one of the finest examples of international cooperation in existence. We have gone from 12 original members to 58 participating countries: 29 consultative members – including the major powers – and 29 observers. The growing interest shown by many states demonstrates that the international community recognises the enormous importance of Antarctica for the global climate and environment.
The Antarctic treaty system
The Antarctic treaty specifies that the continent will be “used for peaceful purposes only” and establishes freedom of scientific investigation in the region. It was signed in 1959 by an initial 12 countries, some of whom had and continue to have overlapping territorial claims.
China, in particular, has made a very strong entry onto the scene. It currently has five research bases in Antarctica and is planning to build a sixth. It possesses a wealth of scientific expertise and substantial resources. This is the sort of transformation the system has undergone in recent decades: countries that previously had no presence on the continent are now investing significantly in Antarctic research.
There are geopolitical interests, of course, but I believe we must maintain and strengthen the spirit of scientific cooperation that has characterised the system for more than six decades.
Do those geopolitical interests ever conflict with environmental goals?
For over a decade, Chile and Argentina have been pushing for a large marine protected area (MPA) in the western region of the Antarctic peninsula. There is broad scientific support, but within the Commission for the Conservation of Antarctic Marine Living Resources [which is mandated to conserve Antarctic marine life], decisions are taken by consensus. So, it only takes one country to oppose the proposal to prevent its approval.
Some argue that further scientific studies are needed. We will continue our research, but we are convinced that protecting this area is essential. Unfortunately, there are also geopolitical and commercial interests linked to krill fishing.
Antarctic tourism continues to grow every year. Are you concerned about this trend?
We are not against tourism. Chile is one of the main gateways to Antarctica, and this brings significant benefits to the region. Furthermore, Antarctic tourism can be a valuable educational tool.
But that growth cannot be infinite. It must be carried out in the most sustainable way possible. Today, there is a growing consensus on the need to monitor the impacts of both tourism and scientific and logistical activities themselves.
If evidence shows that certain activities are affecting specific ecosystems, we will have to limit access or introduce new restrictions.
And is Antarctic research possible without damaging the environment?
With the collaboration of the European Union and the support of Germany in particular, we are developing a green hydrogen pilot plant for our Escudero base, which is our main facility in Antarctica. We currently burn a great deal of oil and diesel to power the base, including for heating.
Green hydrogen
Hydrogen, which does not produce greenhouse gases when burned, can be classified as “green” if it is produced entirely using renewable energy.
This plant would use wind and solar power and could supply up to two-thirds of the base’s annual energy requirements. We are in the final design phase prior to the environmental assessment, carefully considering the impacts on local wildlife. It would require very little fresh water, which we would extract from meltwater lakes.
Other countries have already undertaken similar initiatives. Argentina has a pilot plant up and running, and China also has one in operation. If this works well in Antarctica, it could be scaled up to other extreme environments around the globe. The aim is to demonstrate that it is possible to conduct research and operate sustainably in the world’s most fragile places.
What does the future hold for Antarctica?
The world faces a threefold challenge: climate change, biodiversity loss and pollution. We must continue in our efforts to minimise greenhouse gas emissions and adapt to the changes that are already inevitable. In some cases, we have already passed points of no return, and nature needs a very long time to recover.
That is why the decisions we take during this decade will be crucial in determining what kind of Antarctica future generations will inherit. The most important thing will be to maintain and strengthen the Antarctic treaty system and not to weaken its environmental rules. We must also continue to expand scientific research, because we still know very little about many of the processes taking place there.
The melting point of ice is not up for negotiation. Nor is our commitment to preserving this continent.


