49 2.124. The IPCC has determined that for warming to stay below 2°C, “the total amount of carbon released through carbon dioxide emissions must be less than 1000 billion tonnes.”199 Peer-reviewed research looking into the Carbon Budget has found that eighty percent (80%) of current coal reserves, a third of oil reserves, and half of gas reserves should remain unused from 2010 to 2050, in order to stay within the carbon budget and meet the 2°C warming.200 It is important to note that in relation to the temperature targets, the Climate Vulnerable Forum, under the leadership of the Philippines, has communicated that the target of limiting global temperature rise to 2°C is “‘inadequate,’ posing serious threats to fundamental human rights, labor and migration, and displacement, among other factors.”201 2.125. The petitioners have sought an investigation into not just one corporate group, but groups of companies that carry the largest share of responsibility. Greenhouse gas emissions are “inherently fungible,” meaning that they are “mutually interchangeable in their environmental impact and their effect in the atmosphere, because it is the overall concentration of such greenhouse gases in the atmosphere that ultimately impacts anthropogenic warming.202 Collectively and individually, the respondent Carbon Majors have made a significant, if not the most significant, corporate contribution to climate change leading to human rights harms in the Philippines. 2.126. The second part of causation addresses the challenge of assigning legal responsibility for a problem caused by a large number of greenhouse gas producers. As discussed previously, strict application of legal rules governing liability is neither appropriate nor necessary in this national public inquiry proceeding, given that the Honorable Commission is acting as an investigative body. 2.127. For the purpose of this investigation into the responsibility of the respondent Carbon Majors, the research made on these Carbon Majors demonstrate that the respondents have contributed to the human rights impacts resulting from climate change. As such, the Honorable Commission 199 Carbon Brief (23 October 2013). Carbon briefing: Making sense of the IPCCs new carbon budget, available at https://www.carbonbrief.org/carbon-briefing-making-sense-of-the-ipccs-new-carbon-budget, last accessed on 06 February 2017 (citing IPCC, 2013: Summary for Policymakers); United Nations Environment Programme, The Emissions Gap Report 2015: A UNEP Synthesis Report (Nairobi: UNEP, 2015), xvi, available at http://uneplive.unep.org/media/docs/theme/13/EGR_2015_301115_lores.pdf, last accessed on 08 February 2017. See also ClientEarth’s amicus submission, p. 35. 200 McGlade, et al. (08 January 2015). The geographical distribution of fossil fuels unused when limiting global warming to 2 °C Nature 517, pp. 187–190. 201 Climate Vulnerable Forum (01 May 2015), 20 Nations Call to Strengthen 2 Degrees Climate Goal, available at http://www.thecvf.org/20-nation-forum-questions-unfccc-2-degrees-goal/, last accessed on 08 February 2017; see the amicus submission by Our Children’s Trust which focuses on the use of a “scientific prescription as the standard Carbon Majors and States need to meet in order to uphold the rights of children now and into the future for an environment free of the worst effects of climate change.” Our Children’s Trust’s amicus curiae brief dated 06 December 2016, available at https://www.ourchildrenstrust.org/philippines/, last accessed on 08 February 2017. 202 ClientEarth’s amicus submission, op cit., pp. 42-43.