 Once upon a time, the human enterprise kick-started when we discovered how to make fire. We released the energy encapsulated in wood to make cozy fires for cooking and warming our houses. We released the energy in ancient sunlight stored underground by burning oil, coal and natural gas. We used that energy for moving ourselves around in cars, trucks and aeroplanes. For generating electricity, humans are real pyromaniacs. Our knowledge of how to use fire is vast. It has been vital in helping us to prosper. But this burning releases soot. The soot is everywhere around us. Scientists have shown that it contributes to warming up the globe. Back in the early days, we were a few people living on a big planet. Emissions from our harnessing of fire were not a problem. Today, we are 7 billion people living on what seems like a much smaller planet. Every year, huge quantities of particles, including soot and pollutant gases, enter the atmosphere as a result of incomplete burning of wood and fossil fuels. So what is soot? Scientists use the term black carbon to describe those particles that come from incomplete combustion that are mostly made up of carbon. Carbon dioxide mostly sticks around in the atmosphere for a hundred years or more, but black carbon only lasts a few days. So reducing soot has an immediate effect. It's called black, of course, because these particles are black and they absorb sunlight the way a black t-shirt does in the summer. When black carbon falls on polar ice caps and mounting glaciers, it makes them darker. So they reflect less of the sun's energy back out to space and they absorb more heat and the ice melts faster. My gosh, look at this stuff. I had no idea it was so thick in here. That's amazing. Production of goods and transportation that produces fine particulate air pollution, including black carbon, affects the health of people, often in the poorer parts of the world, and the health of the planet as a whole. What is emitted in one part of the world will have effects in another part. Black carbon emissions from sources, including deforestation and burning of biomass in one area, can alter rainfall patterns over a much wider region. As well as having domino effects by affecting downwind and regionally connected weather systems. Fortunately, the worst sources of black carbon are well known. First, cooking stoves using firewood and kerosene lamps to light up the evenings. Second, farming, burning open fields, grasses and woodlands, and burning of agricultural and forestry waste. Third, diesel vehicles without modern pollution controls and cargo ships burning bunker fuel. Finally, industries like traditional brick kilns and coke ovens that use enormous amounts of firewood, coal and such, or flaring from oil and natural gas production. The question is what can we do about it? We can install particle filters on all diesel engines. More efficient industries like kiln designs that use less energy and less pollution. It may sound like a mammoth task, but it can be done because we have the technology. The trick is how to achieve the implementation. For example, owners need supportive loan structures to help fund upfront investments. Close to 3 billion people worldwide cook their food on open fires and leaky stoves using biomass such as wood, animal dung and crop waste or coal. So a big step is to work together in making a switch to simple, low-cost modern stoves that use clean fuels and are already designed and could be widely distributed. In some villages in Madjah Pradesh, cattle manure is already being used to produce relatively clean biogas for burning, and this releases a lot less soot than directly burning the manure. Among children under the age of five, pneumonia is the most common cause of death worldwide, of which half is caused by toxic indoor smoke. We did realize that the health effects of black carbon on the health of especially women and children, about three million women, died from a related chest and respiratory problems. Uganda was one of the first countries to join America and Sweden to establish the CAC and the benefits of trying to halt the emission of black carbon is tremendous. Then also we look at deforestation, you know, we'll be able to have a better sustainable management of the forest. Deforestation, the change of land use from forest to agriculture, clearing the land off the logging and the basic practice of slash and burn agriculture, creates a lot of soot and other particles and polluting gases with important trans-boundary effects on climate and health. Burning of residues is the cheapest way for the farmer to prepare land after harvest. A solution to the burning of fields is to plow in the residues or collect them to use as livestock feed or for biogas. There are nine specific solutions that scientists have evaluated. If we could drastically reduce black carbon emissions together with other short-lived climate pollutants, we could potentially prevent more than two and a half million deaths per year from outdoor air pollution alone. Another major benefit would be to reduce the rate of global warming and significantly increase our chances to stay within the two-degree target. We would also avoid disrupted rainfall patterns that put agriculture and ecosystems in jeopardy. The only obstacle that you want to highlight is the political well and political commitment, you know, to implement the national plan at the national level. But when we get everybody, you know, political leaders, civil societies and youths on board, then I think we'll be able to cross the barrier and make gains. And in addition, you spend less money on health because people will be healthy. You know, so that is why I believe that public education should be strong and then also bring on board our political leaders to understand the economic gain in trying to reduce carbon emissions. What we need to accomplish can only be done together. This must be a joint effort. We need to be wise. These are impacts that we can deal with now. Time for a global chimney sweep. We all need to be involved.