example.tex

\documentclass{article}
\usepackage{graphicx}
\usepackage{amsmath}
\begin{document}

\title{What is an earth system model?}
\author{Jonny Williams}

\maketitle

\begin{abstract}
An earth system model is basically a traditional physical climate model with additional biogeochemical (earth system) components. In the case of our research, we use atmospheric chemistry, ice sheets (like Greenland) and marine ecosystem dynamics.
\end{abstract}

\section{Definition}


\begin{equation}
\begin{split}
%1+2+3+4+8x+7 & =1+2+3+4+4x+35 \\
%& \Rightarrow x=7
earth\ system\ model &= climate\ model\ +\ biogeochemistry \\
&= atmosphere\ +\ ocean\ +\ sea\ ice\ +\ land\ surface \\
&+ atmospheric\ chemistry\ +\ ice\ sheets\ + marine\ ecosystem\ dynamics 
\end{split}
\end{equation}


\section{Conclusion}
That's it!

\end{document}