There are too many.
Natural resources are limited and we are using them up so fast that they will soon run out.
Problems. Solutions. Concept map. Rising temperature. Pole layers and snow on mountains are melting. Rising sea level. More natural disasters. Some plants and animals are dying out. Reduce the emission of CO2. Use of alternative sources of energy. Safe sources of energy. Comply with the Kyoto protocol conditions.
There are too many industries
The cycle. The results.