Scientific reticence: A threat

The philosophy of science is of rigour and caution. Scientists are trained to look at a problem from multiple perspectives and use all available tools to arrive at the most robust conclusion.

In the case of peer-reviewed journals, scientists and experts assess the validity and accuracy of the findings in an extensive review process. This is the best system we have come up with, over multiple generations, to produce the most accurate and reliable knowledge.

Unfortunately, when it comes to climate change, the need for excessive caution and absolute certainty of results is manifesting as silence from the mainstream science on the worst yet probable consequences and the worst-case scenarios that are looking increasingly likely.

To better understand this, let us consider two examples where this silence is most prominent and also most concerning. The first is related to the debate around the global warming targets set by the United Nations' IPCC in the landmark Paris agreement.

In the 2015 agreement, countries pledged to restrict greenhouse gas emissions "well below" 2 degrees Celsius and 1.5°C, above pre-industrial levels (around 1850s). It was signed by almost all countries of the world. Over the past couple of years, these targets have been largely accepted in the scientific community and among policymakers as "safe" guardrails beyond which we might be in serious trouble.

However, warming, even at 1.5°C, could essentially lock-in irreversible collapse of the Greenland and Antarctic ice sheets and raise global sea-level by multiple metres, argued experts who study land and sea-ice.

While the amount and rate of sea-level rise are uncertain, the basic ice-sheet physics shows that it will certainly happen, at a rate that will be faster than ever seen before. The changes will also be irreversible.

Moreover, some studies have also shown that even a 1.5°C or 2°C temperature rise could be enough to trigger a number of self-reinforcing warming feedback loops. The loops include physical processes caused by rising global temperatures that themselves cause more warming.

Some of such loops have already started rolling, for instance, the vanishing Arctic sea-ice loop. When these processes are triggered they will naturally and certainly lead to greater warming, which would essentially be out of human control.

In light of these facts, the idea that 1.5°C and 2°C are 'safe' seems more like a failure in the effective communication of consequences by the mainstream scientific community.

Second, what is largely ignored in climate debates is the way that the IPCC suggests to achieve 1.5°C and 2°C targets. The global body inherently assumes the use of technologies for carbon capture and sequestration to curb carbon dioxide (CO2) in the atmosphere.

While science shows that we can, in principle, capture CO2 directly from the atmosphere, it has not yet been achieved at the scale that is needed or in a way that is remotely cost-effective.

This raises the question: Are we basing our climate change goals and consequently the future of human civilisation along with that of all the other species on the planet on a technology that does not exist yet?

This would seem like an absolutely critical point of discussion in the climate debate but, the mainstream scientific community — the IPCC, the policymakers and the governments pay little or no emphasis to this.

These are just two examples, which suggest that scientists and experts around the world must speak out more on nuances and the worst-case scenarios that are certainly not obvious to the general public. Given the high stakes and far-reaching human consequences of climate change, it could be argued that it should almost be a moral obligation for the scientists to speak out more than they have been.

"Challenges faced by scientists in finding the right balance between reticence and speaking out are both ethical and methodological," according to a study published last year in the journal Ethics, Policy and Environment.

"Scientists need a framework within which to find this balance. Such a framework can be found in the long-established practices of professional ethics (for example, that followed by engineers and medical practitioners)," it added.

The study discusses plausible reasons (good and bad) for scientific reticence, ranging from a simple and understandable fear of being wrong because of uncertainty in predictions to other reasons like fear of losing funding and facing disapproval from colleagues and the community at large.

It goes on to propose that scientists may be subject to the same code of moral ethics — Duty to Report and Epistemic Privilege — as other professionals in fields such as engineering and medicine.

The Duty to Report says, "[they] must act out of a sense of duty, with full knowledge of the effect of their actions, and accept responsibility for their judgement [in a way that is] open, personal, [and] conducted with the interest of the public in mind."

Epistemic Privilege means that professionals are presumed to have access to knowledge that is not available to other members of society. It is entirely appropriate, and indeed it may be required, for them to speak out — even if there is an appreciable chance that they are wrong.

(Pushp Bajaj is a freelance science journalist. The views expressed are strictly personal)