<span>A small proportion of helium in the crust is helium that was trapped in the Earth when the Earth formed and has not yet escaped. Most helium on Earth, however, forms as a result of alpha decay of uranium and thorium. The emitted alpha particles, once they grab a couple of stray electrons, become helium atoms and can accumulate in gas reservoirs along with things such as methane.</span>
<span>0.032000000 cg
Rounding off ........>
0.0320 cg
The last zero means the measurement is accurate to that digit
</span>
Greenhouse effect is the process of trapping sun radiation in the earth surface, so as to make the planet warm. It is a natural phenomenon in which sun rays that enters the earth surface are re-radiated into the earth surface causing the heat trap in the earth.
In similar manner, green house also trap radiation inside the glass house. The sun rays once reach inside the glass house, strike on plants and objects and reflected back. For entire radiation to escape from the green house, the heat flow between the two points must be proportional to the temperature difference and thermal conductivity. The glass of which the green house are made up, have low thermal conductivity. So, temperature must rise inside glass house so to maintain the heat flow rate of incoming and outgoing radiation.
The green house glass are insulated and they trap the infrared emitted by the objects inside the green house from escaping outside. Since the infrared have longer wave lengths, it is released slowly.
Also, the thermal energy inside the glass house are transferred by convection process. But the glass walls and roof act as insulator, keeping the radiant energy from escaping outside the green house.<span />
Pollution and people littering. Can change everything.