How do the world’s coastlines look in 2025?

At the onset of the millennium, a consortium of distinguished scientists commenced the compilation of a list of risks they deemed most probable to affect the world’s rocky shorelines in the ensuing twenty-five years.

Published in 2002, it contained predictions that, among other aspects, pollution from oil spills would diminish, the prevalence of invasive species worldwide would increase, genetically-modified organisms would adversely affect the ocean, and the repercussions of global climate change would intensify.

After 25 years, the original academics, together with an expanded and diverse team of international experts, have reassessed their predictions and found that many were accurate, either fully or partially, while others did not produce the anticipated effects.

They have also delineated additional risks that have surfaced and intensified since their initial research, with prominent examples including global plastic pollution, ocean acidification, extreme meteorological events, and light and noise pollution.

They have emphasised that, although certain critical issues are anticipated to jeopardise the world’s coastlines by 2050, additional challenges may arise that necessitate diverse degrees of local and global intervention to address them.

The two investigations were conducted by Professor Stephen Hawkins, Lankester Research Fellow at the Marine Biological Association, and co-authored by Professor Richard Thompson OBE FRS, Professor of Marine Biology at the University of Plymouth.

The recent study, published in Marine Pollution Bulletin, involved collaboration with Dr. Kathryn O’Shaughnessy and colleagues from the Marine Biological Association, University of Plymouth, and various organisations in the UK, USA, South Africa, Italy, Ireland, Chile, China, and Monaco.

The researchers integrated expertise from other fields, including climate change, marine biology, plastic pollution, light and noise pollution, and eco-engineering, underscoring the necessity of considering diverse views when addressing environmental problems.

Professor Hawkins, an Emeritus Professor at the University of Southampton, said: “Our shorelines are sentinels for the global ocean and, for many people, their window to what is happening in our seas. Protecting their continued health is essential, but they are constantly facing multiple threats from land, sea and environmental change. Our two studies have shown that over the past 25 years, it is possible to forecast some of the challenges the planet might face in the future and to identify ways they might be addressed. However, there will always be things we can’t foresee – and things that don’t materialise as scientists might expect – and finding a balance will always be key to minimising the impact we have on our planet.”

Professor Thompson, recently recognised by TIME magazine as one of the 100 most important individuals globally for 2025, said: “In the past quarter of a century, most of the world has become more aware of the threats facing our planet. The key questions have always been around the best way of tackling them. Marine scientists have shown that a combination of global and local action can bring about positive change – the successful banning of tributyltin (TBT) by the International Maritime Organization in 2003 being a notable example. As international discussions continue around factors such a Global Plastics Treaty and the most effective ways to reduce global warming, it is important that we recognise past environmental success and build on them.”

What the scientists accurately determined

The incidence and volume of oil spills would diminish.
A greater quantity of food would be harvested from rocky shorelines, both for leisure and economic purposes.
The worldwide dispersion of non-indigenous species would escalate with alterations in global temperatures.
The amalgamation of agricultural intensification and urbanisation along riversides and coastlines would result in heightened sediment influx into rivers, estuaries, and seas.

What the scientists accurately discerned

The projections were inadequately optimistic on the mitigation of the effects of chemical substances, such as tributyltin (TBT), which later became the focus of international regulation.
Scientists recognised the importance of climate variations but did not completely comprehend the many effects they would exert on species and ecosystems.
They also undervalued the significance of extreme weather phenomena attributable to climate change;
Scientists accurately forecasted an escalation in coastal defence constructions to address rising sea levels and intensified storms, although they underestimated the potential repercussions on broader coastal ecosystems.
The recreational utilisation of coastal areas has risen; nevertheless, this trend has not only resulted in negative consequences, but it has fostered a greater appreciation for these environments.

What the scientists miscalculated

Coastlines are currently more susceptible to eutrophication, characterised by elevated levels of nutrients like nitrogen and phosphorus, than they were 25 years prior.
Concerns regarding the escalation of aquaculture, particularly the effects of genetically modified organisms, have thus far been unwarranted;
The expected damage to habitats from offshore renewable energy projects has not occurred.
The effects of UV radiation on coastal organisms were not thoroughly recognised.

What the researchers overlooked

The effects of coastal mining.
Ocean acidification and its possible effects on marine organisms;
The consequences of artificial light pollution.
The consequences of auditory pollution.
Severe flooding and drought occurrences;
The magnitude and consequences of plastic contamination.
The effects of pharmaceutical contamination.
The cumulative impact of several environmental hazards and chemical substances.

Original Publication
Authors: Stephen J. Hawkins, Kathryn A. O’Shaughnessy, George M. Branch, Laura Airoldi, Simon Bray, Paul Brooks, Michael T. Burrows, Juan Carlos Castilla, Tasman P. Crowe, Thomas W. Davies, Louise B. Firth, Keith Hiscock, Stuart R. Jenkins, Antony M. Knights, Olivia Langmead, Kenneth M.Y. Leung, Nova Mieszkowska, Paula Moschella, Ilse Steyl, Svenja Tidau, Mark Whittington and Richard C. Thompson.
Journal: Marine Pollution Bulletin
DOI: 10.1016/j.marpolbul.2025.118214
Method of Research: Observational study
Subject of Research: Not applicable
Article Title: Hindsight informs foresight: revisiting millennial forecasts of impacts and status of rocky shores in 2025
Article Publication Date: 12-Jun-2025