(IMAGE) Elhuyar Fundazioa Caption Measures to improve the environment and the efficiency of the tax system are proposed: CO2 emissions should be taxed and taxes on labor should be cut. Credit UPV/EHU Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.