Articles by Coby Beck

‘Climate is always changing’–That doesn’t mean it isn’t different today

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: Climate has always changed. Why are we worried now, and why does it have to be humans' fault?

Answer: Yes, climate has varied in the past, for many different reasons, some better understood than others. Present-day climate change is well understood, and different. Noting that something happened before without humans does not demonstrate that humans are not causing it today.

‘The null hypothesis says warming is natural’–An inappropriate test, and one that would fail anyway

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: Natural variability is the null hypothesis; there must be compelling evidence of an anthropogenic CO2 warming effect before we take it seriously.

Answer: The null hypothesis is a statistical test, and might be a reasonable approach if we were looking only for statistical correlation between increasing CO2 and increasing temperature. But we're not -- there are known mechanisms involved whose effects can be predicted and measured. These effects are the result of simple laws of physics, even if their interactions are quite complex.

‘Volcanoes emit more CO2 than humans’–Not even close …

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: One decent-sized volcanic eruption puts more CO2 in the atmosphere than a decade of human emissions. It's ridiculous to think reducing human CO2 emissions will have any effect.

Answer: Not only is this false, it couldn't possibly be true given the CO2 record from any of the dozens of sampling stations around the globe. If it were true that individual volcanic eruptions dominated human emissions and were causing the rise in CO2 concentrations, then these CO2 records would be full of spikes -- one for each eruption. Instead, such records show a smooth and regular trend.

(image from Global Warming Art)

‘Mars and Pluto are warming too’–No they aren’t — and what if they were?

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: Global warming is happening on Mars and Pluto as well. Since there are no SUVs on Mars, CO2 can't be causing global warming.

Answer: Warming on another planet would be an interesting coincidence, but it would not necessarily be driven by the same causes.

The only relevant factor the earth and Mars share is the sun, so if the warming were real and related, that would be the logical place to look. As it happens, the sun is being watched and measured carefully back here on earth, and it is not the primary cause of current climate change.