Is our planet really as close to calamity as research suggests?

Lack of reliable data calls into doubt a warning that acidification of the oceans is killing marine life, and news that 2014 was the hottest year, writes Robert Matthews.

Snow falls on the Brooklyn Bridge. EPA

The calendar may be showing a new year but, for environmental scientists, it’s always Groundhog Day. This year has barely started and they are already warning of fresh eco-calamities.

In the journal Science, a team of United States biologists warned that marine species were disappearing at an increasing rate because of human actions and climate change. Meanwhile, last year was officially declared the hottest year in recorded history by Nasa scientists.

Although it’s a similar story each year, there are signs of change – not in the flow of such eco-warnings but in attitudes towards them. Scientists are starting to ask serious questions about the reliability of research.

Scepticism about what appears even in leading journals is nothing new. Researchers routinely suspect editors of rejecting papers simply because they don’t fit the “party line”.

These mutterings have taken a more serious turn with the emergence of evidence to support them. In 2011, a team of journal editors in the US found a clear correlation between journal prestige and the reliability of the research it publishes.

But it wasn’t the expected outcome: it turned out that the more prestigious the journal, the higher the risk of the research being retracted later.

While the level of retractions remains low, it has risen 20-fold in the past decade or so, with the “best” journals leading the way.

Some insist that it simply reflects the difficulty of cutting-edge research. Others blame corner-cutting by scientists under growing pressure to be published in top journals to secure grants and promotions.

But there is also concern about a broader and more subtle issue: the accuracy of the overall image created by research. Is our planet, for example, really so close to calamity as research suggests?

This was the question raised in the journal Nature this month – just as its rival Science published that gloomy review of the state of the oceans.

Nature picked up on the work of an international team of marine biologists who question the doom-laden image portrayed by so much research.

Although there is strong evidence for the reality of some well-known threats, such as overfishing, the same cannot be said for others, according to the team, led by Prof Carlos Duarte from the University of Western Australia.

Take the case of the threat to marine creatures from the acidification of the oceans caused by rising carbon emissions.

As the Los Angeles Times put it in 2012: “Ocean acidification is killing sea life, and we are the culprits.” But according to Prof Duarte and his colleagues, although acidification of the oceans is a potential threat, there’s no reliable evidence that it is already wreaking environmental havoc.

The team lays some blame on the story-hungry media. But they also accuse leading academic journals of being influenced by the media’s agenda.

The solution, they believe, is a proper audit of the evidence that our oceans are under threat: this is “imperative to weeding out the equivocal or unsupported calamities”.

Marine science is hardly alone in making barely justified claims, however.

Following Nasa’s recent announcement that last year was the hottest year yet recorded, climate scientists insisted that it exposed the “myth” that global warming has ceased.

Sceptics have long claimed that the Earth’s annual average temperature has stayed essentially constant since the late 1990s – contradicting the predictions of computer models.

Unsurprisingly, last week’s announcement was hailed by climate scientists as proof that the Earth is getting hotter.

If Nasa is right to claim that 2014 was hotter than all previous years the Earth must, indeed, still be getting hotter. Yet it’s far from clear how Nasa can make such a claim.

Like every measurement, global temperatures are subject to uncertainty – principally caused by the absence of data from large swaths of land and sea. This is reflected in the size of the error bars – the “plus-or-minus” range within which the true value can be assumed to lie.

Small error bars boost confidence that any detected effect is genuine and not the result of chance alone. In contrast, even large effects can be a mirage if the error bars are big enough.

Without these error bars, it is impossible to make sense of any measurement. Yet neither the global temperature nor the error bars appear in Nasa’s public statement. We simply have to take the bare statement that the temperature record has been unequivocally broken completely on trust.

Anyone who takes the trouble to dig deeper will discover, however, that this trust appears to be misplaced.

Dr James Hansen, a climate scientist at Columbia University, has posted a closely argued analysis of the measurements on his website, which states that 2014 did indeed experience the highest global temperature yet recorded.

Crucially, however, he adds that the error bars are so large that 2014 “can be considered a statistical tie” with 2010 and 2005.

Yet environmental science has long appeared to operate on different rules – ones summed up in 1988 by a distinguished climatologist, the late Dr Stephen Schneider, of Stanford University, California.

With global warming starting to make headlines, he expressed his concern about what he called a “double ethical bind” of climate science: whether to convey the complexities accurately and fully, or to “offer up scary scenarios, make simplified, dramatic statements and make little mention of any doubts we might have”.

Dr Schneider said he hoped scientists could strike the right balance “between being effective and being honest”.

It seems at least some of his fellow scientists now fear that they’ve failed.

Robert Matthews is visiting reader in science at Aston University, Birmingham