By Pat Pepper

NCWQ Environment Adviser

Update on Climate Change: The debate on climate change has continued but unfortunately appears to have become more ideological than scientific, perhaps fuelled by American and Australian politicians or aspiring politicians. Lord Christopher Monckton (a well known climate sceptic)’s view that anthropogenic global-warming is a myth is often cited in the popular press. His and similar views are supported by some scientists. These views are just as vigorously refuted by other scientists; Monckton-vs-Scientists.pdf.  Many of the protagonists on both sides appear to be intransigent but the issues raised need serious consideration.

The popular press has made much of the so called hiatus in global warming data accusing America’s National Oceanic and Atmospheric Administration (NOAA) of manipulating the data to exaggerate global warming and timing their publication to influence the historic Paris Agreement on climate change. The U.S. House of Representatives Committee on Science, Space, and Technology accepted this conclusion. However, NOAA results have been validated by independent data from satellites, buoys and Argo floats o

The Conversation has published a series on the science behind climate change and concluded  that human greenhouse gas emissions are resulting in climate changes that cannot be explained by natural causes.  These include articles by

However Dr Judith Curry, President of Climate Forecast Applications Network and  former Chair of the School of Earth and Atmospheric Sciences at Georgia Institute of Technology, concluded that while climate models are useful tools for conducting scientific research to understand the climate system, the current global climate models (GCMs) can not attribute the causes of 20th century warming or predict global or regional climate change on timescales of decades to centuries, with any high level of confidence. Her conclusions are based on

  • substantial uncertainties in equilibrium climate sensitivity,
  • inability of GCMs to simulate the magnitude and phasing of natural internal

variability on decadal-to-century timescales,

  • the use of 20th century observations in calibrating/tuning the GCMs, and
  • the failure of climate models to provide a consistent explanation of the early

20th century warming and the mid-century cooling.

Thus she warns against using GCMs to justify political policies to alter world social, economic and energy systems. Judith Curry, Climate Models for the Layman, 2017, The Global Warming Policy Foundation Briefing 24.

The 2015 edition of the State of the Climate report updates climate indicators such as greenhouse gases; temperatures throughout the atmosphere, ocean, and land; cloud cover; sea level; ocean salinity; sea ice extent; and snow cover show patterns, changes, and trends of the global climate system. Blunden, J. and D. S. Arndt, Eds., 2016: State of the Climate in 2015. Bull. Amer. Meteor. Soc., 97 (8), S1–S275, DOI:10.1175/2016BAMSStateoftheClimate.1  Highlights include

  • Global Temperature: Long-term warming and a strong El Niño contributed to the highest annual combined temperature for ocean and land since reliable records began in the mid-to-late 1800s. Average temperature departures for 2015 compared to the 1981-2010 averages showed Russia and western North America especially warm with only a few areas on land, notably Greenland and north eastern Canada, were cooler than average.
  • Global mean sea level rose approximately 7 cm above the 1993 average in 2015, making it the highest observed since the satellite altimeter record began in 1993. Regional variations highlighted the short-term influence of climate phenomena like the Pacific Decadal Oscillation and the El Niño
  • Ocean heat storage has increased substantially since 1993, hitting a record high in 2015. The heat content in the upper 700 m of the ocean rose more than the deeper ocean (0–2000m) relative to a 1993 baseline. Heat energy rises and falls every few years in response to natural patterns like El Niño and La Niña, but those ups and downs are superimposed on a long-term increase.
  • Global average carbon dioxide concentration (CO2) was reported as 4 parts per million (ppm), a new record high. At Mauna Loa Observatory in Hawaii where atmospheric carbon dioxide has been recorded longer than anywhere else in the world, the atmospheric mole fraction has increased from ~315 ppm in 1958 to 400.8 ± 0.1 ppm in 2015. Human emissions from fossil fuel combustion and cement production are largely considered responsible for this increase.
  • Warm oceans and loss of sea ice are causing big changes in marine life. For example, loss of sea ice is changing the behaviour of Arctic walruses and causing huge declines in some Antarctic penguins species. Warm water fishes are driving polar species out of the Barents Sea. A toxic algal bloom in the Northwest Pacific was the largest in at least the past 15 years. Domoic acid in the algae can build up in shellfish, other invertebrates, and fish leading to illness and death in a variety of birds and mammals that consume them.

As Dr Curry has pointed out there are difficulties in using the current global climate models to predict future climate with any certainty. Nevertheless, progress requires the on going monitoring of environmental data such as greenhouse gases; temperatures throughout the atmosphere, ocean, and land; cloud cover; sea level; ocean salinity; sea ice extent; and snow cover. NOAA compiles this from more than 450 scientists from 62 countries around the world. The global climate indicators help nations to understand the probable or possible impact of global warming on the world and its inhabitants. Regional differences highlight the effect climate phenomena like the Pacific Decadal Oscillation and the El Niño  can have on any long term trend. It is essential this research continues. The USA Committee on Science, Space & Technology are currently holding a Full Committee Hearing – Climate Science: Assumptions, Policy Implications and the Scientific Method. Given the implication for our environment and such unique ecosystems like the Great Barrier Reef it is crucial that in Australia research continues without political and ideological distractions.

Update on Great Barrier Reef (GBR): As noted in previous reportedly global warming is the overriding threat (NCWQ Environment Adviser’s Reports, July 2016, Feb 2016,March 2015); GBR-Coral-Mortality-13-June-2016.pdf; Ocean-acidity levels will continue to increase as the ocean absorbs anthropogenic carbon-dioxide emissions; National Institute for Mathematical and Biological Synthesis (NIMBioS). “Study projects unprecedented loss of corals in Great Barrier Reef due to warming.” ScienceDaily. ScienceDaily, 22 January 2015. <

Coral bleaching has been discussed previously (NCWQ Environment Adviser’s Reports, July 2016, Feb 2016, March 2015, October2014, May2014)), in particular, the most serious bleaching event to hit the Reef on record in 2016, when the Great Barrier Reef Marine Park Authority (GBRMPA) reported the overall mortality to be 22% with about 85%of that die-off occurring in the far north between the tip of Cape York and just north of Lizard Island, 250 kilometres north of Cairns ( the most pristine of GBR). GBR-Coral-Mortality-13-June-2016.pdf  In Global warming and recurrent mass bleaching of corals (2017), Professor T Hughes, James Cook University, with 45 other coauthors shows the footprint of bleaching on the GBR in 1998, 2002 and 2016, using aerial and underwater survey data, with the spatial pattern of heat stress (Degree Heating Weeks, DHWs; °C-weeks) during each mass-bleaching event.

Professor Hughes and his colleagues found water quality and fishing pressure had minimal effect on the unprecedented bleaching in 2016. However these measures could give reefs a better chance to recover. Even good colonizers and fast growing corals can take 10 to 15 years to recover hence assemblage structure of corals is expected to change. A fourth bleaching event could interrupt the slow recovery. The authors urged immediate global action to curb future warming to secure a future for coral reefs.

Many reefs worldwide have declined due to a reduced cover of reef-building corals and an increased abundance of upright macroalgae. Research conducted on Heron Island demonstrated that increasing ocean acidification to elevated CO2concentrations predicted to occur in 2050 and 2100, advantages seaweeds over corals. Vital corals could be significantly harmed by 2050 and killed off by 2100. A common brown algae species found in reefs worldwide was shown to be among those that caused the most damage. Del Monaco, C.. Hay M.E., Gartrell1, P., Mumby P. J.,  & Diaz-Pulido1,G. Effects of ocean acidification on the potency of macroalgal allelopathy to a common coral. Sci. Rep. 7, 41053; doi: 10.1038/srep41053 (2017).  The authors said it was futile to remove seaweeds that have the ability to regrow, and the problem could be tackled only by cutting carbon emissions.

The GBRMPA has warned that more of the reef is showing built-up heat stress than this time last year, just before its worst bleaching event. While cooperative efforts by the entire international community is needed to address climate change and protect coral reefs worldwide the GBR independent review group said Australia needs to do more. They made a number of recommendations aimed at meeting the 2018 water quality, providing more effective regulations to reduce Reef pollution, controlling vegetation loss in Reef Catchments, planning framework to protect the Reef’s outstanding universal values, managing sustainable fisheries, enhancing Reef management, improving monitoring, modelling, evaluation and reporting.. A funding shortfall of $143m to $408m to meet the Reef 2050 Plan actions was estimated. The report also says Australia’s emission reduction targets are “not commensurate with a fair contribution to the reduced global carbon budget” needed to meet Paris agreement targets and protect coral reefs worldwide. It specifically criticises Australia’s support for new coal mines in Queensland that “pose a serious threat to the world heritage area.  Reef 2050 Long-Term Sustainability Plan, Progress On Implementation   Review By Great Barrier Reef Independent Review Group  February 2017

Download the full report HERE!

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