Architects, stand straighter—the goals set up this weekend at the UN COP21 climate change conference in Paris can’t be accomplished without you. Gensler Houston principal Rives Taylor joined thousands of delegates from around the world at the conference and says designers and architects are on the front lines of the battle to mitigate climate change. The Paris agreement sets the goal to reduce the use of fossil fuels and limit the release of CO2 into the atmosphere to slow the rise in the average global temperature. Buildings represent 30% of global greenhouse gas emissions, so upping the sustainability of architectural design can push the dial substantially in the right direction.

The UN acknowledged this major role, hosting the first ever “Buildings Day.” Rives (here with Gensler London managing director Ian Mulcahey) says architects, landlords and property managers should especially focus on becoming better stewards of energy. The talk should go beyond how buildings use electricity and how to reduce waste from phantom loads (energy used when machines are idle/on standby) to include how you handle a site (especially green space) and the materials used in development. There’s a lot of energy connected to these materials, Rives tells us, so it’s time we stop thinking of our buildings and cities as disposable.

PPPs are crucial to accomplishing the climate goals, Rives tells us. He thinks that without the public sector incentivizing better site selection and improving transit and water use, sufficient change isn’t as attractive financially. 145 (primarily North American) mayors in the C40 have committed to tackling climate change; recognizing that it will cost major metros more to mitigate problems caused by climate change than it costs to prevent it. Rives says those mayors particularly need to push property owners to improve existing buildings. Rives was quite moved by this installation at the Pantheon, Ice Watch Paris. The ice is over 25,000 years old and melted over the course of five days, reminding all conference participants about the result if we don’t correct global warming.