Article 2 of the Paris Agreement calls for: "Holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels..." The Agreement was adopted on Dec. 12, 2015, but did not take force until 55 parties, accounting for at least 55% of total global greenhouse gas emissions, joined the Agreement. This goal was reached when the EU nations officially joined the agreement last month.

But an analysis by K&L Gates law firm raises questions about "whether the Agreement itself is even enforceable in the United States given questions regarding its ratification and the pending presidential election." The White House characterizes the Agreement as an executive agreement, not a legally binding treaty that requires Senate ratification.

Robert Watson, a US-British scientist and former head of the UN Intergovernmental Panel on Climate Change (IPCC), admitted to Reuters: "There's no legal enforcement of pledges," but the hope is governments will feel a "moral obligation" and "peer pressure" to act.

Morning Consult rhetorically asks if the Agreement is "Kyoto 2.0." While unlike the 1997 Kyoto Protocol, the new Agreement establishes a maximum temperature increase goal, it is similarly called "binding" without having actual enforcement mechanisms—apart from suspending violators from future negotiations and carbon-trading schemes.

The carbon-trading schemes are themselves controversial. Ecologists have protested that Kyoto carbon credits have been granted to environmtnally destructive mega-projects and unsustainbale agribusiness (including so-called "biofuels"), with many rejecting the concept altogether as a free-market pseudo-solution.

Congressional Republicans have also issued a white paper (PDF) criticizing the low the bar set for China, which is required to "peak" its emissions by 2030 rather than achieving any actual reductions. Agreement proponents counter that under the Kyoto Protocol, "developing countries" (including China) were excluded from emmission caps altogether. The new Agreement is seen as a compromise in the North-South divide that has long stalled climate talks.

Beijing's 2030 committment is in line with the bilateral US-China climate pact announced in 2014. Japan dropped out of its committments under the faltering Kyoto Protocol in 2013. The Kyoto Protocol similarly met with a backlash from conservatives and the fossil fuel industry. It was opposed by the Bush administration and never ratified by the US Senate—depriving activists of a legal tool against stateside polluters.

Researchers who produced a report for the UN Convention on Biological Diversity on "geo-engineering" find it to be a "highly uncertain" prospect, but may be necessary to combat climate change. "Within the Paris agreement there’s an implicit assumption that there will need to be greenhouse gases removed," said Phil Williamson of the UK's University of East Anglia, who worked on the report. "Climate geo-engineering is what countries have agreed to do, although they haven't really realized that they've agreed to do it."

Large-scale geo-engineering may include pouring nutrients into oceans to save coral habitats or spraying tiny particles into the Earth’s atmosphere to reflect sun rays back into space. Geo-engineering proposals have been shunned because of their unpredictable consequences on global ecosystems. (Cantech Letter, Nov. 4; Bloomberg, Oct. 31)

A growing body of evidence suggests that the power plants, buildings, cars, trucks, ships and planes in use today are likely to emit enough CO2 over their lifetime for the world to miss the Paris targets. Coal plants alone could blow the carbon budget for 1.5 degrees C of warming, the lower threshold in the agreement, unless they are shut down early.

"For 1.5 degrees we would have to start retiring things like crazy and we wouldn't be able to build anything new," said UC Irvine scientist Steven Davis. "Two degrees is starting to look equally bleak."

In 2010 Davis and others estimated that the world's existing energy infrastructure had locked in 496 billion tons of CO2 emissions if left to operate for their expected lifetime. By 2013, as hundreds of additional power plants had come online in Asia, the number rose to 729 billion tons.

"By my latest calculations, we're close to 800 billion tons now," Davis said. (ABC, Nov. 18)

From the New York Times, Jan. 17:

Marking another milestone for a changing planet, scientists reported on Wednesday that the Earth reached its highest temperature on record in 2016, trouncing a record set only a year earlier, which beat one set in 2014. It is the first time in the modern era of global warming data that temperatures have blown past the previous record three years in a row...

In 2015 and 2016, the planetary warming was intensified by the weather pattern known as El Niño, in which the Pacific Ocean released a huge burst of energy and water vapor into the atmosphere. But the bigger factor in setting the records was the long-term trend of rising temperatures, which scientists say is being driven by increasing levels of carbon dioxide and other greenhouse gases.

"A single warm year is something of a curiosity," said Deke Arndt, chief of global climate monitoring for the National Oceanic and Atmospheric Administration. "It's really the trend, and the fact that we’re punching at the ceiling every year now, that is the real indicator that we’re undergoing big changes."

As we've noted,  of the 16 warmest years on record since monitoring began in 1880 have occurred since 2001. Which rather precludes the possibility that this is entirely attributable to El Niño.