First the good news! Energy-related carbon dioxide (CO2) emissions are the principal agent of global warming, and after many years of steadily rising, they appear to have plateaued, much to the surprise of many. Recently, the International Energy Agency reported that over the last two years annual global emissions have held steady at about 32 billion tonnes of CO2. The report attributes the trend to improvements in the efficiency with which energy is used and the increasing role of electricity generated by renewables such as wind and solar energy. But the bigger story is that emissions remained steady, while the global economy continued to grow.
The fact that annual economic growth of about 3% occurred without growth in emissions is really good news. For years economic and emissions growth had occurred in tandem, and it had become sine qua non that you can’t have the first without the second. But now that may be changing. We may be able to have economic growth without increased emissions.
Another piece of good news is that the recent trend is being driven by the world’s two largest emitters, China and the US. In China emissions decreased due to a drop in the amount of electricity generated from coal and an increase in electricity generated from renewables, principally hydro and wind. If the trend holds, China will have reached peak emissions more than a decade earlier than its 2014 pledge to do so. In the US emissions also decreased due to reduced use of coal for power generation, enabled by increased use of natural gas and wind. Both nations experienced economic growth over the two-year period, China at an annual average rate of about 7% and the US at about 2.5%.
Now for the bad news! Emissions may have peaked, but they are still large and the amount of CO2 in the atmosphere continues to rise, while the earth continues to warm.
The 21st century has already seen 15 of the 16 hottest years on record, with a new high in 2015 exceeding the previous (2014) temperature record by a large amount. And, there is nothing to suggest that the warming trend won’t continue.
This January and February marked the 9th and 10th consecutive months that the earth’s average monthly temperature set a new record. And, not only did the February temperature surpass the previous high for that month, it also exceeded – by a large amount – the all-time monthly high recorded two months earlier. But, that’s not the whole story.
Warming doesn’t occur uniformly over the earth’s surface, and the first two months of the year experienced Arctic warming more than five times the global average. The unprecedented warming was accompanied by record lows in the formation of Arctic sea ice for January and February.
So, what are we to make of these observations? As we go about our daily business – experiencing natural variability in our weather from hot-to-cold, wet-to-dry, and back again – it’s easy to be complacent, if not dismissive, about the longer term consequences. But the facts are that the earth is warming, that warming affects climate, and that the changes will have serious consequences, if not to us then to our children and grandchildren. To halt this trend, we’re going to have to do much more than holding CO2 emissions steady. In a matter of decades, we’re going to have to reduce them significantly.
Returning to the good news, it’s encouraging that there are pathways to reducing emissions without trashing the economy. We need to embrace them, beginning with energy efficiency and transitioning from carbon-based to carbon-free sources of energy. Technology and capital markets, combined with sound public policy, are poised to do much of the heavy lifting. But, they will have to be augmented by a reduction in the demand for energy, driven by restoration of energy conservation as a core human value, one that takes root in people and nations throughout the world.