But what’s really remarkable is that 2014 set this record without the aid of an El Niño event. El Niño events create conditions in which sea surface and hence global surface temperatures are anomalously hot. We call this part of the Earth’s “internal variability” because these events just temporarily shift heat around between the ocean surface and its depths.
As this graphic shows (click here for an animated version), the last five record hot years of 2010, 2005, 1998, 1997, and 1995 were all assisted by El Niño events.
Posted on 8 January 2015 by dana1981 &
Lately there seems to have been a shift away from climate science denial, toward arguments downplaying the costs of human-caused climate change. Specifically, some economists publishing reports for Bjorn Lomborg’s Copenhagen Consensus Center have argued that we should focus our efforts more on adapting to climate impacts and on other issues, rather than on cutting carbon pollution and slowing global warming.
According to the Climate Action Tracker, current international climate policies will result in a global surface warming of about 4°C. If we act on all conditional pledges, including those recently made by China and the USA, we’ll see about 3°C warming. This (3–4°C) is the range of global warming that the Copenhagen Consensus Center claims would be the most optimal for the global economy.
One might ask, what sorts of climate impacts would we expect to see as a result of this much global warming? Research indicates that the consequences would be quite severe. For example, widespread coral mortality would occur, and 40–70% of global species would be at risk of extinction. Glacier retreats would threaten water supplies in Central Asia and South America. Sea level rise of 1 meter or more would be expected by 2100, with the possibility of destabilization of the Greenland and West Antarctic ice sheets, which would cause much more sea level rise and flooding of coastal communities.
Posted on 30 December 2014 by dana1981 &
From a strictly logical perspective, it’s hard to understand how we can be doing so little to slow global warming. Greg Craven summarized why by examining the extreme possible outcomes in his viral climate ‘decision grid’ video.
In short, if we take action to slow global warming, the worst case scenario involves draconian government regulations that trigger an economic recession. If we don’t, the worst case scenario involves an economic recession too, but also a host of other global and societal catastrophes.
Although Craven doesn’t look at the probabilities of these worst case scenarios, they’re also heavily weighted towards the case for taking action to curb global warming. There are lots of options to slow global warming that don’t involve drastic government regulation, and that can even be beneficial for the economy. If we decide that we’ve gone too far in cutting carbon pollution, it’s relatively easy to scale back government policies.
Posted on 23 December 2014 by dana1981 &
Last week, over 20,000 Earth scientists gathered at the annual American Geophysical Union (AGU) fall conference. They shared their scientific research, ranging from identifying the causes of past climate changes, to estimating the risks of the changes we’re causing now, to how we can successfully communicate the need to mitigate those risks.
Richard Alley (the host of Earth: the Operator’s Manual) summarized the scientific community’s consensus about the threats of abrupt climate change from various potential “tipping points.” Scientists aren’t too worried about a huge methane burp from the ocean or shutdown of the thermohaline circulation (which would cause dramatic cooling in Europe) happening anytime soon. On the other hand, a collapse of the West Antarctic Ice Sheet and large associated sea level rise are becoming increasingly worrying.
This tied into paleoclimate research presented by Aaron Goldner. Atmospheric carbon dioxide levels were at similar levels to today’s (400 parts per million) 15 million years ago during the mid-Miocene period. However, the Earth’s climate was very different. Geologic records give us estimations that sea levels were 25–40 meters higher than today, global mean temperatures 3–6°C hotter, and there was very little sea ice relative to today.
Posted on 12 December 2014 by dana1981 &
A number of Skeptical Science contributors will be presenting at the 2014 AGU Fall Meeting. If you'll be there, come check us out.
|Sunday, 14 December, 8:00 a.m. – 12:30 p.m.||John Cook||Workshop||InterContinental Hotel, 888 Howard St, San Francisco||
Communicating Climate Science Workshop
Deadline to apply is Fri., Oct. 31
|Tuesday, 16 December 2014; 8:00 AM||Andy Skuce||Poster||
Abstract ID and Title: 7106: Emissions of Water and Carbon Dioxide from Fossil-Fuel Combustion Contribute Directly to Ocean Mass and Volume Increases
Final Paper Number: G21B-0444
Session Number and Title: G21B: Variability and Projection of Regional and Global Mean Sea Level Change I Posters
|Tuesday, 16 December 2014; 2:28 PM - 2:40 PM||Dana Nuccitelli||Oral||Marriott Marquis; Salon 13-15||
Abstract ID: 2476
Abstract Title: How to maximize science communication efficacy by combining old and new media
Final Paper Number: PA23B-04
Session Number and Title: PA23B: We Need to Talk: Learning from Climate Experts Who Have Succeeded in the Media
|Wednesday, 17 December 2014; 8:00 AM - 10:00 AM||Peter Jacobs||Oral||Moscone South; 102||
Abstract ID: 11019
Abstract Title: It Ain't (Just) the Heat, It's the Humanity: Increasing Public Understanding of Scientific Consensus and Its Role in Climate Literacy
Final Paper Number: ED31H-07
Presentation Length: 9:30 AM - 9:45 AM
Session Number and Title: ED31H: Climate Literacy: Culture of Science AND Broader Impacts Done Well I
|Wednesday, 17 December 2014: 10:20 AM - 12:20 PM||John Cook||Oral||MS, 102||
|Wednesday, 17 December 2014; 1:40 PM||John Mashey||Poster||Moscone South; Poster Hall||
Abstract ID and Title: 2428: The Machinery Of Climate Anti-Science, Its Efforts Against Education, Top To Bottom
Final Paper Number: ED33B-3513
Session Number and Title: ED33B: Climate Literacy: Overcoming Barriersâ€”Research Outcomes and Best Practices for Supporting Education and Informed Decision Making II Posters
|Wednesday, 17 December 2014; 5:30 PM - 5:45 PM||Julian Brimelow||Oral||Moscone West; 3010||Abstract Title: Hydroclimatological Aspects of the Extreme 2011 Assiniboine River Basin Flood
Final Paper Number: H34C-07
Session Number and Title: H34C: Global Floods: Forecasting, Monitoring, Risk Assessment, and Socioeconomic Response II
|Thursday, 18 December 2014: 01:40 PM - 03:40 PM||John Cook||Oral||MW, 3004||
Scientists Are from Mars, Laypeople Are from Venus: An Evidence-Based Approach to Consensus Messaging
|Thursday, 18 December 2014; 3:00 PM - 3:20 PM||Kevin Cowtan||Oral||Moscone West; 3003||
Abstract ID: 3409
Abstract Title: Biases in the instrumental temperature record: the policy and communications context
Final Paper Number: GC43G-05
Session Number and Title: GC43G: Quantifying Uncertainty in Climate, Earth System, Integrated Assessment, and Impact Models and Observations II
Posted on 8 December 2014 by dana1981 &
A new paper published in the journal Geophysical Research Letters by Griffin & Anchukaitis concludes that the 2012–2014 drought in California was its most intense in at least 1,200 years.
The study used drought reconstructions from tree-ring cores, from the North American Drought Atlas (NADA) and from cores Griffin & Anchukaitis collected from blue oak trees in southern and central California. Blue oak tree ring widths are particularly sensitive to moisture changes. According to Griffin,
California’s old blue oaks are as close to nature’s rain gauges as we get
The study compared today’s drought conditions in California to those reconstructed over the past 1,200 years using the Palmer Drought Severity Index (PDSI), an estimate of available soil moisture. The data showed that California is experiencing its most intense drought in over a millennium,
Posted on 3 December 2014 by dana1981 &
A new study has found that when particulates from small volcanic eruptions are properly accounted for, volcanoes may be responsible for much of the slowdown in global surface warming over the past 15 years.
Sulfur aerosol particulates pumped into the atmosphere from volcanic eruptions cause short-term cooling by blocking sunlight. Until recently, climate scientists thought that only large volcanic eruptions had a significant impact on global temperatures. There haven’t been any big eruptions since Mount Pinatubo in 1991. However, studies published over the past few years have found that even moderate volcanic eruptions can pump significant amounts of aerosol particulates into the atmosphere.
Virtually all research into the climate influence of volcanic aerosols has used satellite measurements of particulates in the upper atmosphere (the stratosphere). These satellite measurements only monitor the volcanic aerosol at heights of 15 km and above. The new paper by David Ridley and colleagues studied the amount of volcanic aerosols in portions of the stratosphere that lie below 15 km.
To do this, the researchers combined data from satellites, ground-based instruments in the AERONET program, and from instruments on weather balloons. The study was co-authored by 17 climate scientists, including some leading experts in aerosol research.
By combining all of these measurements, the scientists found that there is also a significant amount of volcanic aerosol in portions of the stratosphere below 15 km They concluded that for recent eruptions, between 30 and 70% of the overall amount of volcanic aerosol in the stratosphere has come from below 15 km. Since the year 2000, the study estimates that volcanoes have had a cooling influence on global surface temperatures. The likely range of this volcanic cooling influence lies between 0.05 and 0.12°C.
As the authors of the paper note, this cooling influence is not taken into account in the climate model simulations incorporated into the latest IPCC report,
The climate model simulations evaluated in the IPCC fifth assessment report [Stocker et al., 2013] generally assumed zero stratospheric aerosol after about 2000, and hence neglect any cooling effect of recent volcanoes
Although the global surface temperature data have been within the range of model simulations, they’ve been towards the lower end of those model runs over the past 10–15 years.
Posted on 25 November 2014 by dana1981 &
Senators Sheldon Whitehouse (D-RI) and Brian Schatz (D-HI) introduced a climate bill in the US Senate last week. The American Opportunity Carbon Fee Act proposes to tax carbon pollution at the source or at the border for imports, and return 100% of the revenue to taxpayers. The tax would therefore be revenue-neutral, not increasing the size of government.
A revenue-neutral carbon tax has become an increasingly popular proposal for tackling global warming. Liberals have long been on board with requiring that polluters pay for their carbon emissions, but in the United States and a few other countries where climate science is treated as a partisan issue, conservatives have been resistant to this concept.
Research has shown that fear of government regulations is one of the primary reasons conservatives tend to reject the overwhelming scientific evidence for human-caused global warming. A majority of Republicans accept the scientific reality when they realize there are free market solutions available.
The American Opportunity Carbon Fee Act is a free market solution that, because it’s revenue-neutral, wouldn’t increase the size of government. All of the revenue generated would be returned to taxpayers through a variety of possible paths:
Posted on 14 November 2014 by dana1981 &
This week, President Barack Obama and Chinese President Xi Jinping unveiled a secretly negotiated agreement for both countries to slow global warming by pledging to reduce carbon pollution. Specifically, President Obama pledged that the USA would cut its carbon pollution 26–28% below 2005 levels by 2025, while President Xi pledged that by 2030, Chinese carbon pollution will peak and 20% of the country’s energy will come from low-carbon sources.
This agreement received predominantly high praise because it represents the world’s two biggest net carbon polluters taking a leading role in committing to tackle the threats posed by human-caused global warming. China in particular is often used as an excuse by those in the United States and around the world who oppose taking steps to slow global warming.
With the announcement of this agreement, the Chinese president has agreed that his country must begin the process of slowing the growth of and eventually reducing its carbon pollution. The common refrain “nothing we do matters unless China acts” is moot.
However, Republican House Majority Leader John Boehner and soon-to-be Senate Majority Leader Mitch McConnell were among the few who issued negative public statements about the climate agreement. McConnell in particular badly misunderstood the practical consequences of the Chinese and American carbon pledges, saying,
As I read the agreement it requires the Chinese to do nothing at all for 16 years while these carbon emissions regulations are creating havoc in my state and around the country,
Senator McConnell misunderstood the Chinese target of reaching peak carbon pollution levels by 2030 as a pledge to “do nothing.” In reality, China has been developing rapidly with hundreds of millions of citizens rising out of poverty, thus demanding more energy. Much of that demand has been met with new coal power plants; China has added one and a half times the entire US coal power plant fleet in just the past decade. As a result, Chinese carbon pollution has been rising fast.
China could not meet its climate pledge by maintaining business-as-usual (BAU) and doing “nothing.” Quite the opposite; curbing those rising carbon emissions as China’s economy continues to grow will require substantial effort. That’s why President Xi also pledged that 20% of the country’s energy would come from low-carbon sources by 2030.
In comparison, the United States will have a relatively easy time meeting the pledge made by President Obama. US carbon pollution is already about 10–15% below 2005 levels and falling by about 1.5% per year. Achieving the target of 26–28% emissions cuts below 2005 levels by 2025 will only require continuing the current rate at which American carbon pollution is already falling.