Ключевые слова: air, anti, atmosphere, black, bubble, carbon, carbonic, chemistry, clean, cloud, co2, combustion, concept, contamination, damage, danger, dark, decrease, design, dioxide, eco, ecological, ecology, effect, element, emission, emissions, emit, environment, environmental issues, exhaust, gas, global, graphic, greenhouse, icon, industry, isolated, logo, pollutant, pollute, pollution, reduction, sign, smog, smoke, symbol, warming,