Sustainable development faces several significant challenges, including:
1. Climate change: The increasing emissions of greenhouse gases are leading to global warming and environmental disruptions.
2. Resource depletion: Overconsumption of non-renewable resources, such as fossil fuels and minerals, poses a threat to future generations.
3. Biodiversity loss: Deforestation, pollution, and habitat destruction lead to a decline in bio-diversity, which is essential for ecosystem balance.
4. Social inequality: Unequal access to resources, education, and opportunities can hinder progress toward sustainable development goals.
On the day of her examination, Riya sharpened her pencil from both ends as shown below. 
The diameter of the cylindrical and conical part of the pencil is 4.2 mm. If the height of each conical part is 2.8 mm and the length of the entire pencil is 105.6 mm, find the total surface area of the pencil.