The international community began addressing the issue of climate change after the first scientific community warning in 1988. Global public opinion addedthe theme of Climate Change to the international agenda spurred by the testimony of James Hansen, a renowned scientist at NASA's Goddard Center in the US Congress. In 1990, the Intergovernmental Panel on Climate Change (IPCC) published its First Assessment Report and in 1992 the United Nations Framework Convention on Climate Change (UNFCCC) was adopted at the World Summit on Sustainable Development in Rio de Janeiro. Due to the wave of concern arising from the work and preliminary conclusions of the Second Assessment Report of the IPCC in 1995, the Convention is rapidly ratified and entered into force in 1995.

The objective of the UNFCCC is to “stabilize greenhouse gas concentrations at a level that would prevent dangerous interference with the climate system”. The Convention sets out the basic principles that should guide the international fight against climate change. The main principle of the Convention stipulates that countries should contribute by committing to combat climate change in line with their “common but differentiated responsibilities”.


At the first meeting of the Parties to the Convention (Conference of the Parties or COP 1) and despite progress in establishing the overall negotiation framework, it was clear that the Convention would require additional instruments. These instruments should establish mid-term goals and the mechanisms by which emissions reductions should be addressed. In 1995 negotiations started on what would become the Kyoto Protocol at COP 3 in Japan ending two years later.

During these two years rifts between two perspectives on the global mechanism of emissions reductions intensified. On the one hand, the European Union supported the setting of targets and deadlines for emissions reductions, moving ahead with ambitious reduction targets for 2010. On the other hand, the United States emphasized the need to reduce emissions in a cost-effective way, by investing in emissions trading mechanisms (based on the experience of the sulfur dioxide emissions control program).

The outcome of the Kyoto negotiations was a compromise between these two views. Governments agreed to have quantified targets to limit or reduce emissions, subject to international review and to a sanctions system, as intended by the European Union and its allies. In line with the American position, the Kyoto Protocol defined a system based on the quantification and trading of emission rights between countries with targets to facilitate compliance.

As negotiations for the implementation of the Kyoto Protocol progressed (between 1997 and 2001) the European Commission (EC) concluded that the most feasible way to proceed with the implementation of the Protocol in a European context and to enable a genuine European climate policy would be to create a new community instrument. Based upon the American experience and building on its own emissions control policy, the EC explored the idea of a European emissions trading scheme in 1999. A Directive was proposed in 2001 in record time for such a unique legislation and adopted in 2003.

The European Emissions Trading System (EU-ETS) had its first trial period between 2005 and 2007. The goal was to prepare companies for the transaction stage to coincide with Kyoto Protocol’s compliance period (2008-2012). The EU-ETS has become the most prominent example of an international carbon market. It is considered a success because it set a carbon price on the emissions of a major block of countries. The EU learning experience has been replicated, for example, through initiatives like the International Carbon Action Partnership, and emission trading is now considered the main instrument of the European climate policy.

Notwithstanding, the European climate change policy designed to comply with the Kyoto Protocol was not limited to the EU-ETS. A wide range of initiatives have been developed in the European Climate Change Programs. According to the principle of subsidiarity, the European Union has limited action in areas where Member States consider their action to be more effective. However, as early as the 2000s, the European Plans advocated many of the Community policies now in force: either in European infrastructure investment policy, trans-European transport and energy networks; or in the Community approach to the regulation of fluorinated gases which by its impact on certain competitive industrial sectors in Europe was developed at the European level.



The Sustainable Development Agenda was formally adopted for the next fifteen years on September 2015 in New York. The Agenda is the result of over two years of intensive work and negotiations by 193 Member States and as of December 2015, replaced the Millennium Development Goals.

Poverty eradication is a major focus of the Agenda, interwoven with economic prosperity and well-being, social development and environmental protection.

Many issues comprise the notion of sustainable development. Inequality, unsustainable consumption and production, inadequate infrastructure, lack of decent jobs and climate change are at the top of the list. UN Parties underline the importance of moving beyond “business as usual”, to focus on international cooperation, global and multi-stakeholder partnerships, capacity building and statistical tools to measure sustainable development.

The new development agenda insists on the 5 P's (people, planet, prosperity, peace and partnership) and includes 17 goals and 169 targets.

This recent consensus between countries created a positive momentum in the international climate negotiations held in Paris in December 2015, where a new agreement on an international framework to address climate change was reached.


After 20 years of setbacks and progress in global climate negotiations, with increasingly worrying reports from the Intergovernmental Panel on Climate Change, Parties under the UNFCCC finally reached a new global Agreement on Climate Change in 2015. The Paris Agreement sets limits on greenhouse gas emissions as well as addresses other issues related to adaptation to climate change and means to implement an ambitious agenda.

The Agreement is based on the idea that each country should contribute as far as possible to the global resolution of the climate change problem. Those commitments or contributions should be reviewed periodically in light of new scientific findings on climate change evolution. The Agreement is much more comprehensive in its architecture than the Kyoto Protocol. Countries agreed on mitigation (the effort to reduce emissions), adaptation to climate change impacts, climate funding needed to finance the energy transition, technology transfer constraints, among other issues.

It is important to highlight a key component of the Paris Agreement: the objective is to maintain the global average temperature increase to well below 2° C above preindustrial levels while pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels (we are already 1°C above). This implies that global emissions must reach a neutral balance between emissions and removals (absorption by forests and other sinks). This is what we call “carbon neutrality”.


The Paris Agreement assumes from the outset that countries should be encouraged not sanctioned in their commitment to combat global warming. The Agreement is, therefore, based upon a framework of "contributions", i.e. commitments different in nature - some in terms of emissions reductions, others in terms of policies and specific measures, and still others based on metrics other than CO2e, which countries are required to disclose every five years.

The combined effect of each of these "contribution" cycles will be assessed and reviewed by an international process led by the United Nations in order to compare the combined effect of contributions with the desired levels of emissions reductions to achieve the overall goal of carbon neutrality.

In Paris, most Member States submitted their Nationally Determined Contributions (NDCs). They are very diverse due to the absence of a global indication in terms of structure. The following table shows some of the most relevant I/NDCs:

Once contributions have been submitted, a process of "facilitative dialogue" to understand their combined effect will take place. This cycle will be repeated over the next decades.

Source: UNFCCC

Finally, the Paris Agreement also stipulates that Parties should present their Long-term Low GHG Emission Development Strategies by 2020. Some countries have already anticipated their publication:


The Roadmap for Carbon Neutrality is precisely intended to be a contribution to the development of the Portuguese Strategy.