“On Saturday, Switch off Earth Hour”

Rather than switch off lights to show their support for Earth Hour on Saturday from 8:30 to 9:30 pm local time, the public should switch off Earth Hour. While the event has expanded from it’s original focus on the impossible goal of ‘stopping climate change,’ global warming is still a primary rationale.

Earth Hour activists seem not to know that climate has been changing, at times far faster than today, for billions of years, and it will continue to change no matter what we do. Yet their spokespeople have insisted that natural climate drivers such as changes in cloud cover, ocean currents and the Sun are dwarfed by the impact of carbon dioxide (CO₂) emissions from fossil fuels, the source of most of world’s energy consumption. They have told us that climate catastrophe lies ahead unless we spend vast sums to change the way we generate energy.

For this to make sense, at least four conditions would have to be met.

1 – We would have to be confident that future global warming, if it occurs, will be dangerous.

Since 1880, we have seen a warming of just over 1 degree Celsius despite an approximately 42% increase in atmospheric CO₂ levels. Clearly, atmospheric temperatures are not very sensitive to CO₂ levels. Regardless, this small amount of warming has been highly beneficial as we emerged from miserable conditions during the Little Ice Age. So, it is only future temperature rise that could be of concern. And for it to be worthy of public debate, let alone billions of dollars to try to stop, that rise would have to be dangerous.

In 2016, Dr. Tim Ball, former University of Winnipeg climatology professor, asserted that the probability that future global warming, if occurs, will be dangerous is about 2%. His conclusion is supported by the 2015 report of the Nongovernmental International Panel on Climate Change (NIPCC) which asserted: “No evidence exists that… [a warming of 2°C, which the UN says we must avoid] would be net harmful to the global environment or to human well-being.”

But let’s be generous to Earth Hour activists and assume a 10% chance that future global warming, if it happens, will be dangerous. Readers are encouraged to chose their own odds for this and each of the following steps and see what the overall chance of man-made problems would be.

2 – We would also have to know that the cause of this change would be increasing CO₂ concentrations. CO₂ rise is not a concern otherwise since it is not a pollutant.

450 million years ago, CO₂ levels were at least 10 times today’s, but the Earth was stuck in an extended cold period. At other times, it was hot when CO₂ levels were high. At other times, it was neither unusually hot nor cold. There is no consistent correlation between CO₂ and temperature in the geologic record.

And according to the NIPCC report, “No close correlation exists between temperature variation over the past 150 years and human-related CO₂ emissions.”

Ball said that, if dangerous global warming were to occur, the odds of it being caused by rising CO₂ are effectively zero. Natural factors play a far more major role, he and others asserted. However, let’s assume a 10% likelihood for this step.

3 – For Earth Hour’s goals to be rational, we would also have to know that CO₂ levels will actually rise as a result of increasing emissions from fossil fuel consumption.

While most people assume CO₂ concentrations have risen in recent centuries, some scientists dispute this. Ball said in 2016, “The CO₂ level from pre-industrial times was completely manipulated to show a steady rise from 270 ppm to the current 400 ppm. Scientifically valid chemical measurements of 19th century CO₂ levels in excess of those of today were simply ignored.”

He concluded, “we should not assume CO₂ levels will rise in the foreseeable future.” Ball assigned a 20% probability that CO₂ levels will rise. Let’s assume the odds are 75%.

4 – But is this rise, if it occurs, caused mainly by human activities? Or could it come mostly from natural sources such as the ocean?

Ball said there is a 2% chance that any future CO₂ rises will have been caused by industrial activity. Again, we will be generous to Earth Hour activists and say there is 50% chance.

Calculating the product of our probabilities — 10% x 10% x 75% x 50% — reveals that there is only a one in 260 chance that future global warming, if it occurs, will be dangerous and caused by our CO₂ emissions.

But we would still have to know that, were global warming problems ahead, it is more cost effective to reduce CO₂ emissions (mitigation) than simply to adapt. Ball and others assert that there is only a slim chance that mitigation is the most cost-effective approach. In fact, climate analyst Lord Christopher Monckton calculated in 2013 that it is 50 times more costly to try to stop climate change than to simply adapt to it as it occurs. He wrote, “It is at least 50 times more expensive and less cost-effective to mitigate CO₂ emissions by typical measures such as Australia’s carbon tax than to take no action at all today and, instead, to meet the later and far lesser cost of climate-related damage arising from unabated global warming of 3 Cº the day after tomorrow.

So, the likelihood that the climate change-related goals of Earth Hour make sense are miniscule. It’s time that environmentalists kicked climate campaigners off the stage and focussed on problems we know to be real.