The year 2012 was the hottest year in the recorded history of North America, and the past decade was the hottest decade ever measured globally. We have seen the negative effects of climate change firsthand, whether it's the melting Arctic ice cap, wildfires across the western U.S., record floods in Colorado or Superstorm Sandy.
If we want to build a better world within the next 20 years, former Vice President Al Gore says that climate change is our biggest challenge.
See also: How to Follow Social Good Summit Online
To a crowded auditorium eager to hear him speak at the Social Good Summit Monday afternoon, Gore announced this year's 24 Hours of Reality event, taking place Oct. 22 to 23, to identify the costs of carbon pollution and the solution that can "change the course of our future."
"Mother Nature is speaking up loudly and clearly," Gore says. "Will the world be played for a fool again? I don't think so. I think that we are right at a political tipping point, because people are hearing from their parents and grandparents and elders that it's never been like this before."
According to Gore, we put 90 million tons of carbon pollution into the atmosphere every 24 hours. The accumulated amount of manmade global warming in the atmosphere traps as much heat every day as would be released by 400,000 Hiroshima bombs. That, Gore says, is what raises both the air temperature and the ocean temperature.
The Climate Reality Project, the movement Gore started to work toward fixing the climate crisis, aims to provide hopeful solutions. Every year, Climate Reality hosts a 24 Hours of Reality event, during which the team travels the world to measure climate impact. This year's initiative hopes to hold those who pollute accountable, rather than putting the cost on the general public.

"We are already paying the price of carbon, so it is high time that we put a price on carbon. The course of civilization between now and 2030, and beyond, is going to be shaped by us," Gore says.
"It is simply not acceptable for major companies to mimic the unethical strategies of the tobacco companies in presenting blatantly false information in order to protect a business model. We have to put a price on that denial ... We need to let the polluters pay that price."
The Climate Reality Project and 24 Hours of Reality plans to bring people together from around the world — economists, scientists, doctors, nurses, et al. — to figure out real solutions.
Gore urged the Social Good Summit community to take part in this conversation.
"Mention the elephant in the room," he says. "Speak up!"

The Social Good Summit is where big ideas meet new media to create innovative solutions and is brought to you by Mashable, The 92nd Street Y, The United Nations Foundation, The United Nations Development Programme, The Bill and Melinda Gates Foundation and Ericsson. Held during U.N. Week, the Social Good Summit unites a dynamic community of global leaders to discuss a big idea: the power of innovative thinking and technology to solve our greatest challenges.
Date: Sept. 22 through Sept. 24 Time: 12 to 6 p.m. each day Location: 92nd Street Y, 1395 Lexington Ave., New York, N.Y. Tickets are sold-out, but tune into the Livestream.
BONUS: 10 Empowering Apps for Social Good
Gone are the days of daring your friends without consequences. When you challenge your friends to Budge, the person who loses the challenge needs to donate an agreed upon amount to a charity of the winner's choosing.
Available on iOS.
Charity Miles lets you raise money for your favorite causes while walking, running or biking. The app's corporate sponsors donate 25 cents for each mile you walk or run, and 10 cents for each mile you bike.
Charity Miles is available for iOS and Android.
With every photo you share, Johnson & Johnson donates $1 to a cause of your choosing. The Donate a Photo app, available on iOS and Android, also lets you follow your friends' photos, so you can keep up with your social life.
Great for foodies, photographers and humanitarians, this iOS app adds a great cause to your foodstagrams. When you dine and snap a food shot at one of the participating restaurants -- which, for now, are only in New York -- a meal is donated to a non-profit feeding schoolchildren in South Africa.
In this free iOS game, you'll travel with Maya, an Indian girl, as she navigates the slums in search of clean water. The longer it takes her to find water, the more school she misses.
The game was created in partnership with charity: water, which lends in-game missions and video scenes to the app.
Did you know that with the money you save cooking three of your own meals, you could fund someone's HIV medicine for three months? Instead is an iOS app that shows you how much you can save with simple tweaks in your lifestyle. Once you make those cheaper decisions, Instead encourages you to donate to a non-profit out of your savings.
My Life as a Refugee is an app for iOS and Android created by the U.N. High Commissioner for Refugees (UNHCR). It lets anyone around the world experience life fleeing from conflict or persecution. Through beautiful illustrations, you'll read the stories of the app's many characters, who have been separated from their loved ones and have experienced hardships.
The Recyclebank app, available for iOS and Android, rewards you for recycling. The gamification of recycling awards points that you can redeem in stores and in the app.
Forget daily deal apps -- there are apps that give back while giving you a great deal. TangoTab, available for iOS and Android, donates meals to food banks every time a diner purchases one of its restaurant deals.
Eager for a new volunteer program? This iOS app brings the online volunteer network onto your smartphone. It has a sleek interface that will help you find great opportunities to give back near you.
VolunteerMatch lets you select which skill you're looking to use to volunteer, so you can lend your expert web design or managerial skills, for example.
Image: Mashable, Casey Kelbaugh