Citizens ask the expert in climate physics

24 11 2020

In the first of two consecutive interviews with climate-change experts, authors, editors and readers of the Spanish magazine Quercus have a chat with Ken Caldeira, a global-ecology researcher at the Carnegie Institution for Science (Washington, USA). His responses attest that the climate system is complex, and that we need to be practical in dealing with the planet’s ongoing climate emergency.

PhD in atmospheric sciences and professor at Stanford University (USA), Ken Caldeira has pioneered the study of ocean acidification and its impact on coral reefs (1) and geoengineering solutions to mitigate anthropogenic climate change by extracting carbon from the atmosphere and reflecting solar radiation (2, 3). He has also been part of the Intergovernmental Panel on Climate change (IPCC) and assessed zero-emissions scenarios (4, 5). To the right, Ken manoeuvers a drone while collecting aerial data from the Great Barrier Reef in Australia (6). Source.

SARS-Covid-19 is impacting the world. In our home country, Spain, scientists argue that (i) previous budget cuts in public health have weakened our capacity to tackle the pandemic (7), and (ii) the expert panels providing advice to our government should be independent of political agendas in their membership and decisions (8). Nevertheless, the Spanish national and regional governments’ data lack the periodicity, coherence, and detail to harness an effective medical response (9). Sometimes it feels as if politics partly operate by neglecting the science needed to tackle challenges such as the covid pandemic or climate change.

Having said that, even if a country has cultivated and invested in the best science possible, people have difficulties coming to terms with the idea that scientists work with probabilities of alternative scenarios. As much as there are different ways of managing a pandemic, scientists differ about how to mitigate the ecological, economic, and health impacts of a high-carbon society.

Thus, a more and more common approach is to make collective assessments (elicitations) by weighing different points of view across experts — for instance, to establish links between climate change and armed conflict (10) or to evaluate the role of nuclear energy as we transition to a low-carbon energy-production model (11). The overarching goal is to quantify consensus based on different (evidence-based) opinions.

The questions we here ask Ken Caldeira could well have different answers if asked of other experts. Still, as Ken points out, it is urgent that (of the many options available) we use the immense and certainty-proof knowledge we have already about climate change to take actions that work.

Interview done 23 January 2020 

We italicise each question and the name of the person asking the question and cite one to three relevant publications per question. For expanding on Ken Caldeira’s views on climate change, see a sample of his public talks here and here and newspaper articles here and here.

Read the rest of this entry »

Throwing the nuclear baby out with the fossil-fuel bathwater

6 02 2018

Lynas TwitterA really important paper was just published in Science Advances by Elizabeth Anderson & colleagues.

The team’s paper, Fragmentation of Andes-to-Amazon connectivity by hydropower dams, pretty much highlights what many pragmatic environmentalists have been stressing for years — so-called ‘renewable’ technology rolled out at massive scales (to the exclusion of other technologies like nuclear power) can really endanger biodiversity.

As environmental campaigner, Mark Lynas, rightly points out, renewables, with sufficient base-load back-up by technologies like nuclear, are so far ahead of other combinations (particular, regionally specific mix ratios notwithstanding) in terms of what they can potentially achieve for biodiversity, that our society’s blind push for 100% renewable (instead of 0% carbon), is doing far more environmental harm than good.

It is a case of throwing the nuclear baby out with the fossil-fuel bathwater. Read the rest of this entry »

Greenies can be pro-nuclear

7 10 2013

happy-nuclear-powerPublished today on The Conversation by Ben Heard & me.

The IPCC fifth climate change report lays out a carbon budget that we must follow if we’re to keep the world under a temperature rise of 2C over pre-industrial levels – the widely accepted level above which lies catastrophic climate change. According to the report, we can “spend” 1,000 gigatonnes (Gt) CO2 in total. We’ve already spent more than half, and at the current rates we are on track to blow the other half in 30 years.

Not only is human society at risk from this unprecedented rate of warming, the ecosystems on which all life is based are also seriously under threat.

So it’s a timely moment to look at how we could avoid burning through our carbon budget, including controversial options such as nuclear energy.

This week marks the beginning of the Australian tour of a new documentary, Pandora’s Promise. The film aims to dispel myths and spark a debate about whether you can be simultaneously “pro-nuclear” and an environmentalist.

Renewable failure

Even with the best of intentions to reduce the magnitude of future climate disruption, decades of focus on carbon pricing and the promotion of renewable energy sources cannot hide our failure to provide scalable, large, reliable sources of clean (low or emissions-free) energy.

Today, wind turbines and solar panels combined deliver only around 3% of total electricity consumption in Australia, with coal providing 70 %, and gas another 20 %. The contribution of renewable energy has decreased over time – in 1960 renewable energy contributed 19% (largely thanks to hydropower) and coal 76 %. Total renewable energy contribution today, including hydro, has shrunk to 9%.

This is thanks, in substantial part, to the mismatch between dispersed, intermittent wind and solar technologies and the large, continuous fossil fuels we need to replace.

These sobering statistics are in no way an argument to abandon renewables, but they are evidence of a serious failure to date and point to near-certain failure in future. Passing the blame to media, fossil fuel interests or other favoured scapegoats makes us feel good and is no doubt deserved. But we must also cease avoiding uncomfortable truths about the inadequacy of the solutions we have advocated to date. Read the rest of this entry »