Tag Archive | "global warming"

The Science Behind Climate Change and Extreme Weather Events

Photo Credit: Dr. Kevin E. Trenberth

Photo Credit: Dr. Kevin E. Trenberth

The environment in which all storms form has changed owing to human activities.”

– Dr. Kevin E. Trenberth, Distinguished Senior Scientist

What is the science behind climate change? What explains Category 5 hurricanes? Dr. Kevin E. Trenberth, Distinguished Senior Scientist in the Climate Analysis Section at the National Center for Atmospheric Research (NCAR), offered his perspective on these questions in his recent talk at the University of Denver Sturm College of Law.[1]

Dr. Trenberth obtained his Sc. D. in meteorology in 1972 from the Massachusetts Institute of Technology.[2] He was a lead author of the 1995, 2001 and 2007 Scientific Assessment of Climate Change reports from the Intergovernmental Panel on Climate Change (IPCC), and shared the 2007 Nobel Peace Prize, which went to the IPCC.[3]

The World Meteorological Organization (WMO) and the United Nations Environment Program (UNEP) established the IPCC in 1988.[4] The IPCC’s principal function is to provide policymakers with scientific bases for climate change, as well options for adaptation and mitigation.[5] Hundreds of experts contribute to the information needed to understand climate change in the IPCC reports.[6] The IPCC’s reports underlie negotiations under the United Nations Framework Convention on Climate Change (UNFCCC).[7] The Conference of the Parties (COP) meets annually to review the UNFCCC’s implementation and to adopt instruments ensuring its effective implementation.[8]

Dr. Trenberth acknowledges that the data on changes in the climate are of 700-802 mixed quality and length.[9] However, taken together, the data tells a compelling story about the extent of the human role in climate change.[10] Today, research on climate change demonstrates that 97 percent of “actively publishing climate scientists agree: Climate-warming trends over the past century are extremely likely due to human activities.”[11]

 Observable Changes in Climate

What have observed in terms of climate change since the Industrial Revolution? There is an increase in carbon dioxide and in the planet’s temperature.[12] Glaciers are melting and sea levels are rising.[13] Artic sea ice areas are decreasing, with 2012 as the lowest on record, which is denoted in the lowest point in the graph by NCAR below.[14]

The National Aeronautics and Space Administration (NASA) takes satellite images of artic sea ice.[15] According to their animated time series, the 2017 photograph below reveals less artic sea ice than the1979 photograph.[16] Further, according to the most recent IPCC report in 2014, “Human influence on the climate system is clear, and recent 70-246 anthropogenic emissions of greenhouse gases are the highest in history. Recent climate changes have had widespread impacts on human and natural systems.”[17]

DJILPPic1

 

 

 

 

 

 

DJILPPic2

 

 

 

 

 

 

 

 

 

DJILPPic3

 

 

 

 

 

 

 

 

 

 

 

 

Measures

 Scientists use observations and theoretical models to understand changes in the climate. Key observable measures include the Global Surface Temperature and Ocean Heat Content. In the following sections, these measures are defined and analyzed.

Global Surface Temperature

According to the National Oceanic and Atmospheric Administration (NOAA), a temperature anomaly signifies a departure from a specific reference value.[18] Reference values allow for a more accurate representation of temperature patterns within regions.[19] A positive anomaly indicates an observed temperature warmer than that reference value.[20] A negative anomaly reflects an observed temperature cooler than that reference value.[21] The global temperature anomaly provides a measure based on average global temperatures compared to a specified reference value.[22] The global surface temperature is based on land surface and sea surface temperatures.[23]

If you look at the graph below, this measure reveals an overall upward trend (see black line across the graph) with 2016 as the warmest year on record.[24] In 2016, there was a 1.2 degrees Celsius rise above pre-industrial levels.[25] The international community set a goal through the Paris Agreement (2015) to keep the global mean surface temperature increase below two degrees Celsius above pre-industrial levels and to limit the temperature increase even further to 1.5 degrees Celsius.[26] Government policies and actions must be directed at maintaining the global surface temperature to reach the Paris goal.[27]

DJILPPic4

 

 

 

 

 

 

 

 

 

 

 

Ocean Heat Content

The Earth’s energy imbalance drives the ongoing global warming and can best be assessed from changes in Ocean Heat Content.[28] Ocean Heat Content measures the heat stored in the ocean. It is measured from the surface of the ocean to 700m, which reflects the 1967 to 2002 measures, and from the surface to 2000m, which reflects 2003 to present.[29] If the ocean absorbs more heat than it releases, the Ocean Heat Content increases. According the graph below, the ocean heat content has been increasing since the 1990s, with 2017 as the warmest year on record.[30]

Further, natural variability is the element of uncertainty in climate changes within a certain range because the components of the climate are never in perfect equilibrium.[31] Climate scientists are therefore interested in deviations from that natural variability to explain other causes of climate change. Natural variability, according to Dr. Trenberth, is a lot less for Ocean Heat Content than for global mean surface temperature.[32]

DJILPPic5

 

 

 

 

 

 

 

 

 

 

Climate Models

 In addition to the measures above, climate scientists can run models to assess differences in global surface temperature in the absence of an increase of carbon dioxide in the atmosphere.[33] For Dr. Trenberth, these models demonstrate that around the 1960s and 1970s, global warming emerged from the noise of natural variability.[34]

Extreme Weather Events

What explains hurricanes such as Harvey, Irma, and Maria? Hurricanes are natural, but they are intensified because of changes in the climate.[35] According to Dr. Trenberth, hurricanes feed off the sea temperatures.[36] When the ocean warms, water from the surface of the ocean then evaporates to cool the ocean, adding warm moist air, or vapor, into the atmosphere.[37] Rising air condenses the water vapor, which produces strong updrafts, drawing in more air.[38] The updraft creates clouds that lead to thunderstorms.[39] Then air spirals into the thunderstorm at the bottom and then out at the top.[40] The storm strengthens and strong surface winds increase evaporation, rainfall, and energy into the storm.[41]

For Dr. Trenberth, the increase in Ocean Heat Content results in evaporative cooling, which releases additional moisture into the atmosphere.[42] That moisture results in heavy rain that releases latent heat.[43] That heat is redistributed by winds and can radiate.[44] The moisture from an evaporating ocean gives fuel to hurricanes, creating an extreme weather event.[45] For example, if we look at Hurricane Harvey, the total rainfall, which was 140.7 mm, or 4.65´1020 J of latent energy in rainfall, matches the amount of Ocean Heat Content lost after the hurricane.[46] Therefore, Dr. Trenberth determined that if the Ocean Heat Content had been less, then rainfall would have been less.[47]

Dr. Trenberth’s Conclusions & Recommendations

Dr. Trenberth emphasizes that human activities are the dominant cause of the observed warming of the Earth.[48] Accordingly, he suggests that there is likely a human fingerprint on the extreme nature of recent hurricanes.[49] Hurricane Harvey caused approximately 30 billion USD in damages (insured and uninsured losses)[50], Hurricane Irma caused approximately 50 billion USD in damages (insured and uninsured losses)[51], and Hurricane Maria exceeded 63 billion USD damages (estimate for insured losses only).[52]

Dr. Trenberth recommends that to avoid the costs of hurricanes, we should: stop building in flood plains, adhere to strict building codes, manage drainage systems, plan evacuation routes, and plan emergency shelters.[53] He also stresses that while we do need mitigation and adaptation strategies to respond to climate change, we also need information.[54]

Read more on Dr. Trenberth’s work here: http://www.cgd.ucar.edu/staff/trenbert/#research.

Meera Nayak is a Staff Editor with the Denver Journal of International Law & Policy, and a 2L at the Sturm College of Law.

_________________________________________________________________________________________________________________

[1] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[2] http://www.cgd.ucar.edu/staff/trenbert/#research

[3] http://www.cgd.ucar.edu/staff/trenbert/#research

[4] http://www.ipcc.ch/

[5] http://www.ipcc.ch/

[6] http://www.ipcc.ch/

[7] http://www.ipcc.ch/

[8] http://unfccc.int/bodies/body/6383.php

[9] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[10] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[11] https://climate.nasa.gov/scientific-consensus/#*

[12] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[13] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[14] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[15] https://climate.nasa.gov/vital-signs/arctic-sea-ice/

[16] https://climate.nasa.gov/vital-signs/arctic-sea-ice/

[17] https://www.ipcc.ch/pdf/assessment-report/ar5/syr/AR5_SYR_FINAL_SPM.pdf

[18] https://www.ncdc.noaa.gov/monitoring-references/faq/anomalies.php

[19] https://www.ncdc.noaa.gov/monitoring-references/faq/anomalies.php

[20] https://www.ncdc.noaa.gov/monitoring-references/faq/anomalies.php

[21] https://www.ncdc.noaa.gov/monitoring-references/faq/anomalies.php

[22] https://www.ncdc.noaa.gov/monitoring-references/faq/anomalies.php

[23] https://www.ncdc.noaa.gov/monitoring-references/faq/anomalies.php

[24] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[25] https://www.ncdc.noaa.gov/cag/global/time-series/globe/land_ocean/ytd/12/1880-2017

[26] http://unfccc.int/paris_agreement/items/9485.php; https://public.wmo.int/en/media/press-release/provisional-wmo-statement-status-of-global-climate-2016

[27] http://climateactiontracker.org/

[28] http://advances.sciencemag.org/content/3/3/e1601545.full

[29] https://www.ncdc.noaa.gov/cdr/oceanic/ocean-heat-content

[30] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[31] https://www.ipcc.ch/ipccreports/tar/wg1/042.htm

[32] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[33] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[34] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[35] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[36] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[37] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[38] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[39] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[40] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[41] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[42] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[43] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[44] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[45] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[46] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[47] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[48] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[49] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[50] http://www.bbc.com/news/business-41075704

[51] https://www.reuters.com/article/us-hurricane-irma-corelogic/corelogic-estimates-hurricane-irma-property-damage-at-42-5-65-billion-idUSKCN1BU28T

[52] https://www.wsj.com/articles/hurricane-maria-caused-as-much-as-85-billion-in-insured-losses-air-worldwide-says-1506371305

[53] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

[54] http://www.cgd.ucar.edu/staff/trenbert/Presentations/Trenberth_Steamboat_Jan18.min.pdf

Posted in 1TVFA Posts, 2Featured Articles, DJILP Staff, Meera NayakComments (0)

The Fight Against Climate Change: The Paris Agreement Ratified by 75 Countries

Graph prepared by James Hansen Makiko Sato from data collected by NOAA and NASA.

Graph prepared by James Hansen Makiko Sato from data collected by NOAA and NASA.

On October 5th the requirements were met for the Paris Agreement (PA) to enter into force. This milestone was triggered when more than 55 countries representing 55% of global greenhouse emissions (GHG) ratified the Agreement. The PA has had tremendous international public and private support following its adoption by the 197 Parties to the United National Framework Convention on Climate Change (UNFCCC) in Paris on December 2015. Within days of this announcement, the Earth’s atmosphere reached its own notable milestone. The National Oceanic and Atmospheric Administration (NOAA) issued a statement that for the first time in three million years, atmospheric levels of the heat trapping gas, carbon dioxide measured 400 ppm. The dramatic rise of CO2 levels is a considerable departure from the stable CO2 levels of 278 ppm that allowed for a comfortable climate for human life to evolve. NOAA noted that this change coincided with global deforestation and burning of fossil fuels in the 1850s and the 1950s respectively.

The PA seeks to mitigate increasing GHG emissions and cap global temperature rise well below 2° Celsius (3.6° Fahrenheit) of pre-industrial levels and to pursue efforts to limit temperature increase to 1.5°Celsius. Through the PA, countries individually and voluntarily pledge Intended Nationally Determined Contributions (NDCs) to achieve this cap. Further, the PA calls for efforts towards adaptation of the impacts of climate change and provides a managerial vehicle for the investment needed for a sustainable low-carbon future. The PA will come into force on November 4, 2016 and will set into motion the first meeting of the governing body of the PA, the Conference of the Parties serving as the meeting of the Parties to the Paris Agreement.

In November of this year, the CMA will meet at the Conference of Parties 22 (COP22) in Marrakech, Morocco. One of its tasks will be to ensure global commitments for the $5 to $7 trillion needed to support these efforts by 2020. $100 billion has already been pledged by developed countries to developing countries. The private sector is also playing a major role in these efforts investing billions of dollars to green markets. The collaborative efforts of both the public and private sectors towards accelerating GHG emissions is truly a remarkable moment in our world’s history.

Speaking the day that the 55% milestone was reached, the United Nations Secretary-General Ban Ki-Moon said, “Global momentum for the Paris Agreement to enter into force in 2016 has been remarkable. What once seemed unthinkable is now unstoppable.” For the sake of future generations, let’s hope that the global momentum to reduce emissions overtakes ever increasing heat trapping gases.

Entry into force of the PA is no doubt timely, given both milestones. With no peak of carbon emissions in sight and with ever increasing and severe weather events, the money and effort put in by public and private entities is certainly needed to adapt to the effects of our changing climate and to develop sustainable methods for future generations.

Posted in 1TVFA Posts, 2Featured Articles, Jeremy BellaviaComments (0)

Climate Change: Is There Hope for an International Response?

Nearly 200 world nations launched a new round of talks in Doha to review commitments to cutting climate-altering greenhouse gas emissions. (Global Post)

Was Hurricane Sandy the result of global warming?  Many scientists are reluctant to directly attribute this and other recent superstorms to global warming.  However, it is very likely effects from climate change are influencing the severity of these storms.  With the scientific world approaching a consensus that human activity is contributing to climate change, pressure is mounting on the international community to respond.

Delegates, nongovernmental organizations, and environmentalists from over 200 countries are currently converging at the United Nations climate-change summit in Qatar to debate the issue.  The underlying goal of the conference, ending on December 7, is to slow global warming, specifically to “pave the way toward a world treaty, to be signed in 2015, aimed at slowing global emissions of heat-trapping fossil-fuel pollution enough to keep the planet’s temperature from rising by 2 degrees Celsius (3.6 degrees Fahrenheit).”  Scientists fear a sustained increase above two degrees Celsius will lead to a chain reaction of extreme events, such as rapid sea level rise, widespread flooding, extreme weather, and food shortages.

However, skepticism surrounds the summit.  For one, ongoing global temperature increase is feared to be all but certain.  A recent study funded by the National Science Foundation concluded that “[d]espite efforts to reduce greenhouse gas emissions, global warming and a greater increase in sea level are inevitable during this century.”  Also, the summit’s goal of extending the 1997 Kyoto Protocol appears to be losing ground.  The treaty, which expires at the end of 2012, is the only legally binding U.N. pact addressing global warming.  It calls on wealthier governments to limit carbon emissions through restrictions on their businesses and citizens.  However, the U.S. declined to ratify the original treaty, and now others – including Russia, Canada, and Japan – are unlikely to sign the extension.

While the effect of the U.N. summit is currently in doubt, it should be noted that many individual countries are taking domestic action to reduce their contribution to climate change.  For instance, Mexico adopted a national law to reduce carbon emissions by thirty percent from “business-as-usual levels” by 2020, and fifty percent from the 2000 levels by 2050; South Korea approved a mandatory carbon trading program affecting some of its biggest polluters; and the European Union recently put into effect a program to reduce carbon pollution from aviation.  As for the United States, fuel efficiency standards were sharply improved under the Obama administration, and the President has expressed plans to adopt a more proactive approach to global warming during his second term.

However, climate change is a global issue requiring an international response.  Unfortunately the U.N. summit in Qatar appears unlikely to produce immediate results. The only hope is that it will lay a foundation for future cooperation and resolutions.

Frank Lawson is a 4LE and Board Member on the Denver Journal of International Law and Policy

 

Posted in 1TVFA Posts, 2Featured Articles, DJILP Staff, Frank LawsonComments (0)

Critical Analysis: Competition for Arctic Resources Heats Up

 

Ice Breaks in the Arctic

In 2007, a submersible named Mir descended over 4 km to the bottom of the Arctic Ocean and planted the Russian flag under the North Pole. The news broke all over the world and prompted fears of potential violent confrontations between arctic countries. Thus far, such fears have not been realized, but with Arctic sea ice coverage set to hit a record low this year, the Arctic region is not only literally heating up, but commercially. According to satellite data from the US National Snow and Ice Data Center, the Arctic sea ice coverage is already less than the previous record in 2007. Without doubt, the most commonly heard lament is the catastrophic impact this will have on polar bears and other arctic wildlife. What flies under the proverbial radar, however, is the impact that falling sea ice levels will have on global commerce, trade, and politics.

Despite historic trends showing that freshly opened regions often succumb to conflict between competing countries, many believe increased activity in the Arctic will be unusually peaceful. For instance, 95% of Arctic mineral resources are within agreed upon national boundaries. Additionally, operating costs in the Arctic are still enormously high, which encourages joint venture projects and cooperation. Lastly, the Arctic countries, comprised of the United States, Canada, Russia, Norway, and Denmark, want to give the least amount of excuses possible to the rest of the world to begin meddling in the region’s affairs.

As the thaw continues, countries are looking to profit. Canada’s Prime Minister, Steven Harper, recently stated that he believes the “Arctic’s natural resources will propel Canada’s future economic hopes.”  The Arctic’s potential has even attracted those from thousands of miles away. The Chinese energy company, CNOOC, has proposed to purchase the Canadian oil and gas producer, Nexen, for $15 billion, in an attempt to access the rich resources in the Yukon and Arctic regions.

The most tantalizing of all, especially for Russia, is the prospect of a new short-cut for trade routes. Last year, the 162,000 tonne tanker, Vladimir Tikhonov, traveled from a Northern port in Russia through the Bering Strait in just seven and a half days, making it the largest vessel to ever traverse the Arctic. Just recently, China set its own record as its first icebreaker traveled along the Russian coast and arrived in Iceland. Passage through the Arctic Ocean remains fraught with danger. It is expensive and icebreakers, needed to facilitate the journey for large commercial vessels, are scarce. The danger of becoming stranded notwithstanding, commercial traffic through the Arctic is increasing every year. Though this spells dollar signs for companies and governments, aboriginal and environmental groups are concerned that aggressive development in the region spells disaster for fragile ecosystems upon which many native populations depend.

The thaw continues, and how countries respond to the competing commercial and environmental interests will unfold only as quickly as the ice melts.

Posted in 1TVFA Posts, 2Featured Articles, DJILP StaffComments (0)


University of Denver Sturm College of Law

Posts by Date

May 2018
M T W T F S S
« Apr    
 123456
78910111213
14151617181920
21222324252627
28293031  
Resources