There seems to be increasing confidence that a substantive agreement will be reached at the December 2015 UN climate change conference in Paris (often referred to as "COP21"). This will establish a framework for all nations to take action on climate change.However, this will not be a classic "top down" international treaty, as negotiators have learnt lessons from previous, unsuccessful, attempts for a genuinely global climate change agreement. Instead, the proposed agreement is a collective statement of intent to take meaningful action on climate change, working from the bottom up.The agreement can be likened to a flotilla of nations, moving towards a common destination, but at different speeds and on different individual courses. This contrasts with a classic international treaty, which places every nation on the same vessel, course and speed.What would an effective agreement be?Key features of an effective agreement would include:A clear intention to keep the global 2 degrees goal within reach, even if current national commitments don't yet add up to the emission cuts needed for this. The 2 degree level should avoid the worst effects of climate change.A set of legally binding rules, so that the many actions across nations can be assessed and compared on a common basis.A process of regular five yearly reviews to allow commitments to be increased as technology advances.Mechanisms for mobilising finance for the measures required.What progress has been made?Following the last conference in Lima in 2014, countries have been preparing submissions detailing their proposed emission reductions, known (snappily) as "Intended Nationally Determined Contributions" (INDCs for short). Around 140 INDCs have been submitted to date, covering more than 80% of emissions. All the major emitting countries have put forward commitments, which is a key step forward.However, initial assessments suggest that the combination is only sufficient to limit the global temperature increase to 3 degrees. A review process will be essential to keep ratcheting up ambition and pressing down emissions.Adaptation or mitigation?The agreement currently places equal weight on adapting to the effects of climate change and mitigating further climate change. Adaptation and mitigation strategies will both require massive investment in new and upgraded infrastructure.While much work is already in progress on both, a formal agreement is likely to spur on additional efforts over the coming decade and beyond.What does it mean for civil engineers?The implications for civil engineers are clear – the profession will play a major role in delivering action on climate change. As long as a globally agreed framework and effective policy measures are in place, engineers will plan and deliver the infrastructure that will help us mitigate and adapt to the impacts of climate change.Our energy engineers will continue to develop low carbon, renewable energy production. Our transport engineers will help deliver solutions for reducing CO2 emissions. Water engineers will continue to secure fresh drinking water and food production in the face of drought impacts, and our flood defence engineers will protect coastal cities and communities against rising sea levels. All of us must reduce waste and improve efficiencies across the board.Specifically within the energy sector, much of the focus has been on storage, including its potential to support renewable generation and reduce emissions. Our recent report – Electricity Storage: Realising the Potential – explores the current barriers and makes recommendations of how to improve its prospects.The Paris conference begins on 30th November and merits close attention. If successful, it could turn out to be one of the most significant events in the history of civil engineering.Full details are available on the UNFCCC website.