Ключевые слова: air, art, atmosphere, background, carbon, chemistry, cloud, co2, color, colorful, concept, contour, design, dioxide, eco, ecology, effect, emission, emissions, energy, environment, exhaust, formula, gas, global, graphic, greenhouse, icon, illustration, isolated, label, line, linear, lineart, logo, logotype, outline, pollute, pollution, reduction, sign, smog, smoke, symbol, warming, web,