Constructivist theories grew out of the work of a couple of Russians around the time of the Russian Revolution. It is radical subjectivism dressed up as science, and has no scientific credibility whatsoever. It is used by radical educators to push their barrow that nothing the teacher knows is worth the student learning and that all knowledge is innate. It's bullsh*t. Theories like this rot are part of the reason that the bottom has dropped out of Western education and we have a generation who can't write. This should be resisted by any educator with an interest in educational excellence.
A world treaty on climate change will be delayed by up to a year and is likely to be watered down because countries with the highest greenhouse gas emissions are refusing to commit to legally binding reductions.
Money invested in protecting nature can bring huge financial returns, according to a major investigation into the costs and benefits of the natural world