COP21: 9 questions for a renewable energy expert

Stanford University Professor Mark Jacobson

(CNN)If there's anyone who can help us figure out how to address climate change, it's probably this guy.

Mark Jacobson is a Stanford University professor and director at The Solutions Project, which aims to help the world move to 100% renewable energy.
So it's no wonder so many of you joined us on Facebook to bring him your most pressing questions and concerns about Earth's future. Here are some of the questions you posed along with Jacobson's answers, live from the COP21 climate conference in Paris.
Question: With so many billionaires and government bodies that have invested so much in these industries that cause or produce pollutions, the issue of climate change will only seem like an anti-profit call to their investments. How do you hope to go about addressing their fears?
    Jacobson: Changing to an entirely clean, renewable wind, water, solar (WWS) energy economy will create 22 million more jobs worldwide than the fossil economy and save society $25-50 trillion per year in health and climate costs while stabilizing energy prices and reducing international conflict. Not changing will result in the opposite, thus damage economies and nations and cause people to lose more.
    Question: Why instead of only working to curb emissions, can't we work on building back forests by genetically engineered trees to increase CO2 uptake and O2 release?
    Jacobson: That could help a little, but CO2 is only 42% of the warming problem and controlling CO2 alone does not help solve the 4-7 million deaths per year from air pollution or energy security problems associated with fossil fuels. The primary solution that solves these problems is transitioning to an electric, non-combusting energy society.
    Question: Using renewables is a great idea, but it seems like only the wealthy can convert. What can be done to eliminate that so alternative energies are affordable to everyone?
    Jacobson: There are many newer lower-cost electric cars already out plus planned in the next year. Also, solar can be leased at no upfront cost right now. Also, everyone can afford energy efficiency measures.
    Question: Do you think the transition to 100% renewable energy will be expensive?
    Jacobson: Transitioning to 100% clean, renewable wind, water, solar (WWS) energy has an up-front cost for wind turbines, solar panels, etc. and for storage and transmission, but there is zero fuel cost, so the average "business" cost if the energy turns out to be the same or less than that of a 2050 fossil-fuel economy, around 11 U.S. cents/kWh. However, because fossil fuels also cause health costs of around 15 cents/kWh and climate costs of another 9 cents/kWh for a total of 24 cents/kWh, the total social cost of energy (business+health+climate) cost for WWS is 11 cents/kWh versus 35 cents/kWh for fossil fuels, so WWS is much cheaper.
    Question: What assurance can you give that this is actually doable? There's a lot of rhetoric at the U.N. climate talks in Paris about getting to 100% clean energy by 2050, but what does it really take to do that?
    Jacobson: This is doable because it is based on existing technologies that can be deployed quickly and are currently low cost. Wind and utility-scale PV, for example, take 2-5 years from planning to operation to install and are currently the cheapest forms of new electric power in the U.S. for example. Nuclear, on the other hand, takes at least 10-19 years between planning and operation and costs 2.5-4 times more than wind or utility-scale solar.
    Question: Do you think the recent floods in Chennai, India, are a result of climate change?
    Jacobson: It is hard to pin specific events on climate change, since by definition climate is the average of many weather events either in time or space. However, we expect more precipitation worldwide because of the higher water vapor content in the atmosphere due to higher sea surface and land temperatures increasing water evaporation, and precipitation equals evaporation on the global scale.
    Question: Will your plan effectively help the drought in the western U.S.? If we have no water to work with, that effectively takes out one mode of power. I'd like to see a way designed to help replenish water sources.
    Jacobson: Climate change is creating more severe variations in weather, including drought and floods in some places. Implementing 80% WWS by 2030 and 100% by 2050 should reverse climate change such that CO2 is back to 350 ppm by 2100, and temperatures should respond accordingly. Other benefits of converting include reducing international conflict, allow[ing] countries to produce almost all their own energy, will create more distributed energy reducing terrorism risk, and will create 22 million more jobs than it destroys. Hydro in these plans can be shifted to other energy sources if necessary, but in many cases it is not used to its full capacity.
    Question: I'm more interested in autonomous vehicles. I'll take a gas burning autonomous car over a clean electric car any day.
    Jacobson: How about an electric autonomous car? Electric cars are 80-86% efficient; gas cars are 17-20% efficient, so require 4-5 times more energy in their fuel than is needed in electricity. As a result, the "fuel" cost of an electric car is 80 cents/gallon equivalent versus 3-4 dollars/gallon for a gasoline or diesel car. As such, someone driving 15,000 miles per year for 15 years saves up to $20,000 in fuel cost over that period. Plus, electric cars are safer since they don't explode, have more crush space, and have lower centers of gravity so don't roll so much.
    Question: Climate change is a hoax!
    Jacobson: One does not need to believe in climate change to want to transition energy. Transitioning will eliminate 4-7 million human deaths per year from air pollution worldwide, create 22 million more jobs than it costs, stabilize energy prices, reduce international conflict, reduce terrorism risk, move 4 billion people from energy poverty, and reduce costs to society by over 60%.
    Some questions have been edited for length and clarity. You can read the full chat over on Facebook.