The American Meterological Society has released State of the Climate 2015. I would love to take a week and scrutinize each and every map and figure, but alas…

One thing that caught my eye was by far the coolest cover art I have ever seen on a scientific report! Seriously, have a look if you look at nothing else!

Another thing that caught my eye is the idea of an “accelerating hydrologic cycle”. I hadn’t heard that before, but I suppose it makes sense if there is more energy/heat being added to the Earth on balance.

Overlaying a general increase in the hydrologic cycle, the strong El Niño enhanced precipitation variability around the world. An above-normal rainy season led to major floods in Paraguay, Bolivia, and southern Brazil. In May, the United States recorded its all-time wettest month in its 121-year national record. Denmark and Norway reported their second and third wettest year on record, respectively, but globally soil moisture was below average, terrestrial groundwater storage was the lowest in the 14-year record, and areas in “severe” drought rose from 8% in 2014 to 14% in 2015. Drought conditions prevailed across many Caribbean island nations, Colombia, Venezuela, and northeast Brazil for most of the year. Several South Pacific countries also experienced drought. Lack of rainfall across Ethiopia led to its worst drought in decades and affected millions of people, while prolonged drought in South Africa severely affected agricultural production. Indian summer monsoon rainfall was just 86% of average. Extremely dry conditions in Indonesia resulted in intense and widespread fires during August–November that produced abundant carbonaceous aerosols, carbon monoxide, and ozone. Overall, emissions from tropical Asian biomass burning in 2015 were almost three times the 2001–14 average…

Records of observation-based global evaporation only span the satellite era. This has not prevented a handful of studies from attempting to disentangle the impact of climate change on trends in evaporation. Jung et al. (2010) suggested a reversal in the rise of evaporation since the late 1990s, which was later shown to be a temporary anomaly caused by ENSO (Miralles et al. 2014b). Nonetheless, these studies, together with more recent contributions (Zhang et al. 2015, 2016), have indicated the existence of a slight positive trend over the last few decades, in agreement with expectations derived from temperature trends and global greening, and the theory of an accelerating hydrological cycle…

The discussion of “biomass burning in Indonesia” caught my eye because it is one thing to read about it, and another to get a lungfull of it as my family did when living in Singapore in 2013. It was shocking – you looked out the window and could barely see the next high rise maybe 50 feet away. We had a newborn baby at the time and decided to go to the trouble of traveling interanationally with him to get him out of there. And it sounds like this year’s pollution was worse than what we experienced.

The tendency for increased drought in the tropics during El Niño leads to increased release of CO2 from increased tropical wildfires. In 2015, out-of-control agricultural biomass burning was exacerbated in Indonesia (see Sidebar 2.2) by ignition of the subsurface peat. These changes in terrestrial carbon storage likely contributed to the record 3.1 ppm increase in atmospheric CO2 at Mauna Loa Observatory from 1 January 2015 to 1 January 2016. The previous highest annual increase of 2.9 ppm occurred in 1998. Biomass burning in Indonesia also led to regional increases in atmospheric carbon monoxide, aerosols, and tropospheric ozone in 2015 (Sidebar 2.2). Huijnen et al. 2016 suggest that the 2015 carbon emissions from the Indonesian fires were the largest since those during the El Niño year of 1997 (section 2g7; Fig. 2.60), although still only 25% of the 1997 emissions…

The 2015 Indonesia fire season began in August, and by September much of Sumatra, Kalimantan, Singapore, and parts of Malaysia and Thailand were covered in thick smoke, affecting the respiratory health of millions of people. Visibility was also reduced to less than 10% of normal over Borneo, and large parts of the region could not be seen from space, as was documented for previous fire events in that region (Marlier et al. 2013; Wang et al. 2004). Preliminary estimates suggest that greenhouse gas emissions from the burning (in CO2 equivalent) exceeded Japan’s 2013 emissions from fossil fuel combustion (Van der Werf 2015). Even after the worst of the 2015 Indonesian fires were no longer burning, the remaining pollution stretched halfway around the globe.

Comparing the emissions to those from a major industrial economy like Japan puts the staggering scale in perspective. Beyond the effect on human health and the climate, this is also a loss of diverse tropical ecosystems and fertile soils.